The 075 would be a great fit for the Russian navy (as would many other mainstay PLAN classes tbh), but the Russians depend too much on arms exports to risk the reputational damage of being seen to buy major weapons systems from a former customer like China. I think the fear is that if Russia buys 075s, they will struggle to sell any warship afterwards.
Add to that no desperate operational need for LHDs and I just don’t see them going for it no matter how well suited it might be for them.
Similarly, Russian helicopters are nowhere as attractive to China these days as in the past, with Naval Z20s and Z10s coming along nicely.
TBH, LHDs might just be what the Chinese domestic helicopter industry needs in terms of sustained long term orders to justify significantly increased production capacity.