Actually, let's put this into the greater context. Who is Gongke? Why is an insider telling us stuff about things that should normally be classified? Is he really who he says to be, or is something else going on?
Well, let's start with Gongke. So far, his claims seem to have been of great accuracy, so we know he knows something. So then why is he telling us these things?
Two possibilities. Gongke is doing it for the accolades. Note on the thread that he's being described as big brother, divine spirit, etc, and is generally being begged for information. Psychologically, this is quite flattering. But if he's doing so without government authorization, covering his ass is of paramount importance and being vague allows him to "leak" without actually having leaked, both from a bureaucratic perspective and an intelligence perspective.
The other possibility is that he's a deliberate agent of the Chinese government, beyond his mere employment, and what he's telling us about is a managed PR scheme. Compared to official statements, what Gongke is dealing in is rumor, albeit highly reliable rumor. However, as rumor, everything he says has plausible deniability. Let's say that Gongke claims that the WS-15 project will be done in 2 years. But if the project is not done in two years, who takes the blame? Is the government / AVIC blamed for delays? Or do we blame Gongke instead for not knowing what he's talking about? Or what if Gongke says something not believable, like the HMD on the J-20 allows the pilot to shoot long-range high-intensity lasers out of his eyes. That may have some credence, but allows the government to make disinformation claims without tying its own credibility to the task.
More likely, it's some combination of both. Gongke is likely leaking information at the government's behest, but he is doing so because he is now essentially a rock star on CJDBY. With that in mind, let's return to the text under exegesis (because that is what we are doing, applying literary theory to internet rumors).
Let us put this another way. Is Gongke's text ambiguous? For instance, his initial statement has a group of ambiguities:
"最近3年大部分人是没机会看见15整机了"
最近 can be read to mean recently, or in the near future. It is not a clear term, if he wished to say recently, he could have said 进来 to disambiguate. The 了 at the end of the comment doesn't help; it can mean that the sentence refers to something already completed, or something that has just completed, meaning that the statement could be read as past tense or future tense.
The next statement is the crux of our argument, but as by78 says, it is understood as "designed for" based on context, because, say, in a motorcycle shop, we could read this as referring to something installed on a vehicle. More problematic, and something we have not discussed, is 许多人, or many people. Who is this "many people"? Why does Gongke say "有机会看见" (have the opportunity to see) as opposed to 看过 (have seen)? Does that mean it's something we've already seen? Or something that people have had the opportunity to see, if they want to? And when by78 states context; it could have been disambiguated with 为, interpreting it as that people have seen the WS-15 installed on the J-20 is invalid only because Gongke said it's not valid, and because the WS-15 project, from other rumors, seems to be delayed.
Lastly, if we look at the last statement, Gongke says that if you count the nozzle petals correctly on the WS-15, and if the petal count is not that of the WS-10 or AL-31, you can conclude it's a WS-15. Of course, the alternate interpretation is not grammatical, but we have the 15 petal TVC nozzle to support it.
Taken this way, Gongke's delivered us an ambiguous statement, but to what end?
Obviously, we should first look at it as a speech act. What we know definitely is that Gongke is telling us to pay close attention to the petal count on released J-20 pictures, and if they're neither 16 or 18, the J-20 is flying with WS-15.
Beyond that, we should look at statements and interpretations as parsimoniously or aggressively as we need.
Most parsimoniously, what Gongke is saying comes out to this:
The majority of people have not, to date, been able to see the entire WS-15 engine (i.e, leaked pics are inaccurate as the engine is changing), but some people have been able to see the WS-15 nozzle. And if you see a J-20 nozzle with a petal count dissimilar from the AL-31 and WS-10 (16 and 18 respectively), you will know it's a WS-15.
Less parsimoniously, we also have the following interpretations:
-The WS-15's final appearance will not be leaked in the next 3 years.
-The WS-15 nozzle is leaked (see J-10B TVC nozzle).
-The WS-15 has already been flying on the J-20.
-The WS-15 has been installed on the J-20.
-The WS-15 has 15 petals on its nozzle.
For the first statement, we simply need to wait 3 years; if a finalized WS-15 comes out before then, or within 2 years, this interpretation is negated and Gongke meant "before".
For the second statement, we do not know definitively if the J-10B TVC nozzle will be the WS-15 nozzle, but it is definitely of interest. And it is quite possible that from the J-10B TVC leak to WS-15 IOC on J-20s, the TVC nozzle will be changed further. But this statement can be corroborated if, when the WS-15 IOCs, the WS-15 has the J-10B TVC nozzle.
For the third statement, I've looked at a lot of J-20 nozzle pictures, and they're all WS-10 or AL-31Fs. However, given the Zhurihe rumor (for the military parade), if insiders later report that the WS-15 was flying then, that statement is corroborated (i.e, the soldiers marching in the parade are 许多人). Given the WS-15's apparent status in limbo, this is somewhat unlikely though.
For the fourth statement, the way to corroborate this would be if next 1/11, we notice a petal count on the J-20's nozzles that do not match the WS-10 or AL-31, i.e, the WS-15 has entered flight testing.
Of the preceding three statements, Gongke has categorically denied these claims, but Gongke could simply have been aiming to protect his job and freedom by not confirming an ambivalent claim.
For the last statement, we simply need to see a J-20 with WS-15 and to be able to count the petals on the WS-15.
Of course, all of these need further corroboration to be true, but what does Gongke get by not explicitly stating these things? Well, Gongke is only liable for the most parsimonious interpretation. For the others, he can't be "wrong" as he never explicitly said any of this; if things turn out otherwise, he's not liable because he didn't actually say any of this. On the other hand, if any of these statements are corroborated, he earns further respect as someone who is in the know, while not being bureaucratically liable for the leaks as he didn't explicitly say any of this.