To admit I'm not that optimistic. IMO both differ too much esp. in regard to the revised intake and I can't think that they would use a 200x demonstrator, more likely a 201x prototype, which are closer to the LRIP-standard.
I think a 201x prototype is also possible, but I've always thought the 201x prototypes could be inducted into active duty at some point, or they be used for more development testing, and are thus more valuable. They're probably keeping the 2001x prototypes around for a reason, and because the airframes are older and demonstrators they're probably more disposable. If it really mattered they could modify the intakes, though admittedly that'd be more work. A 201x prototype would of course provide more accurate flight and performance data, but maybe they could move onto a 201x frame after validating on a 200x, though that would be an extra and potentially redundant step. They could just integrate the engine straight into a J-20B airframe for development and production testing after testing and validating the engine on a 200x frame.
Anyways, it was just a wayward thought. Fwiw though I hope they don't skip the IL-76 testbed, because that would be a lot more transparent for us and make it easier to track the progress of the engine.