Why do you think the new missile is called PL-15 and the "old" PL-15 is now only considered a PL-12 variant, especially in regards to the capabilities of the missile?
Doesn't it make more sense for the "old" PL-15/PL-12 variant to still have the range and capabilities that you listed for it in your previous PL-15 entry, and for this "new" PL-15/PL-XX to instead be fielding newer capabilities? (edit: especially considering the previous rumours of Pl-15 tested aboard J-20, J-16 and J-10B/C etc, it makes sense that the "PL-15" mentioned in those previous rumours are the crop wing PL-12 variant/"old" PL-12 -- OTOH this "new" PL-15/PL-XX appears to be an entirely new missile which the previous rumours of the "old" PL-15 do not appear to accuarately describe)
I'm also sure you've seen the CDF thread with the study investigating a missile with a semi ballistic trajectory with a range of >300km that likely corresponds to this missile.
Wouldn't it make more sense for the "old" PL-15/PL-12 variant to still retain the same dual mode AESA/200km range and compatible with both J-20 and 4+ generation fighters, while this "new" PL-15/PL-XX is intended for super long range roles >300km and only used aboard 4+ generation fighters (unable to fit into J-20)?
edit: also, the suspected ImIR aperture I think is also a very viable guidance method for stealthy targets.