Never say never. China has made a habit of surpassing our expectations in recent decades.
The J36 and H20 are both going to be cornerstone platforms for the PLAAF going forwards, but a high altitude hypersonic regional strike bomber can still certainly find its own niche in a future PLAAF orbit alongside the J36 and H20.
China can certainly afford it no problem, and such a platform would certainly dovetail nicely with a lot of cutting edge tech China has been developing that doesn’t really fit the J36, J50 or H20.
Nope. As previously mentioned, the J-36 made the JH-XX redundant.
Firstly, as I've explained before - The JH-7 (or the JH designation itself) was a special case in the PLA history, born during the times when the PLAAF needed a successor to the H-5 and Q-5, and the PLAN desperately needed ways to effectively confront and counter enemy forces (airborne and surface) at sea. Back then, the only platforms available to them are J-6s, J-7s and J-8s - All of which have limited ranges and/or limited strike capabilities. The H-6s are meant for striking more important (operational/strategic) targets, let alone being not as attritable as smaller warplanes by nature. Thus, the JH-7 was born.
If anything - The J-16 can be considered the worthy successor to the JH-7. And yet, nobody calls it JH-16.
Besides, as combat warplanes evolve to become even more versatile and multirole-capable (which can be seen as essentially one of the fundamental capabilities of modern combat warplanes) - The need to develop yet another separate warplane type naturally becomes obsolete. This hasn't even include the introduction of UCAVs into the aerial warfare systems of today and in the future.
That's why JH-XX isn't really needed.
As for the question of affordability: Being able to afford is one thing. Being able to diligently allocate resources to those programs, platforms and systems that are actually useful and truly matter to China's overall warfighting strategy is another.