We won't hear much or see the Y-20 based AWACS until all the major work is done and completed more or less.
From the day Y-20 LRIP started (most likely before that) they would have been planning an AWACS based on the Y-20 aircraft. If desired and suitable, then this is a work in progress. Unlike most nations, China doesn't talk that much about what it plans on doing in the military field until it's already mostly done. You won't get brochures and pamphlets about this amazing new product they want to propose formally lol. Unless of course it's an export only thing or starts off as an export only thing and then gains PLA attention.
We'll see Y-20 based AWACS when it's at least test flying near completion prototypes. We didn't see WZ-8, GJ-11, hypersonics, or almost every single major piece of equipment until they're in testing. Or due to leaks and other political reasons some stuff is actually talked about and known well before testing is shown in public e.g. J-20.
If the desire is to incorporate the latest technologies and better integrate a Y-20 based AWACS into PLA, especially what future PLA is developing towards, the program would take many many years if not a decade or more to refine. I suspect they'll refine over time and do a program => programA =>programB sort of thing but the first would be the breakthrough piece a la Type 346 => Type 346A => Type 346B. This means such a Y-20 AWACS would have been in the works for a long while.
A lot of military watchers are also unfortunately some of the dumbest people around. Lots of opinions that are based on a "I see it now so it must only recently have been done because I didn't hear about it before this therefore it has to be crap because they just put whatever together and called it a day otherwise we would have heard or read about it". This logic applies to many because they're used to seeing some other nations announce and pamphlet decades before they get a full scale prototype and decades before they get the thing into active service.
Just because something is quiet doesn't mean there's no project for it and there's no work on it. If Y-20 is suitable for a AWACS and that's what PLA wants, it is developed and like the H-20, it'll only be publicly unveiled in at least flight testing phase if not already in service like WZ-8 and DF-17 was.