^ I do dispute that. The j-10b is analogous to f-16e. F-16cds don't have aesa nor irst or the integrated ECM offered by the e version and the j-10b.
And I think even if j-20 entered service without the supercriising WS-15 it can still be considered 5th gen if it has everything else. F-35 doesn't have supercruise remember.
Also the world isn't moving to 5th gen and ucavs... Only the us. No other country has a ucav program that is definitiely going to enter service in the near future (china isn't too far behind in this regard either, sac is supposedly going to fly an x-47b analogue this year or next), and the jsf partners will receive their first f-35s only a few years before the plaaf gets the first j-20s, maybe even after. And the Pak fa is only a year ahead of j-20 at best and its future is dependent on Indian funding too.
J-10b will be competitive with all other aircraft aside from the raptor and f-35... Basically any other air force aside from the USAF. The UK, France, Europe, Russia and India will all have mostly 4th gen fleets by late this decade and the US too most likely. The j-10b will remain relevant, even after j-20 enters service.