Would make sense to go with 3 x WS15 more or less 'as is' rather than develop new and improved versions (or new engines altogether) if there's an urgent requirement to get a long range air dominance or striker into service ASAP.
What we've seen doesn't look entirely dissimilar to this:
View attachment 140315
Another reason to go with 3 engines is that the J-XD production run will be pretty small.
The US NGAD programme was only talking about 200 fighters accompanied by much lager numbers of CCAs. So I see a notional Chinese requirement being say 300 as an upper limit.
So if the requirement is for a 60tonne MTOW aircraft and given the small production run, is it worth developing an entirely new class of larger engine, just to keep the number of engines at 2?
Or would it be better to standardise on the existing WS-15 form factor and benefit from existing economies of scale?
We'll likely see 1000+ J-20s being produced, and presumably they can benefit from a future adaptive cycle engine? It would be similar to the previous plan to replace and update the F-35 engines in the future.
We also had previous public comments from the DOD that for the NGAD programme, they were seriously considering larger, even bomber size aircraft