Kinda like with the aliens, unless you see if in person, best to suspend your belief. In any case, this is all just prototype test flying. As far as we know, the competition for PLAAF's next generation fighter is ongoing. It'll be pretty sweet to see what CAC's prototype looks like but even though it's flying around in whatever testing ground, it's still something the authorities could decide they want to hide and we won't see if for years despite it flying around today or yesteryear.
The hypersonic glide vehicles were flying around for a long time before we saw one example - DF-17. We only heard of the projects and test flights from various Chinese and American sources. Didn't make those years between 2010 and 2019 mean they weren't zooming around in the skies somewhere above China. Same with the 6th gen prototypes. I would say it's only worth checking this thread for the discussion and the whole military watching hint dropping to establish which rumours and sources have repute for future reference.
