Plenty of demand outside the US. Why would the hyperscalers not buy the chinese RAM for all of their datacenters across the world besides the US one?

Rising supply from China will impact prices even in countries where there are tariffs.

The best Chinese RAM on the market is 50% larger and requires more power and thus emits more heat, as it is a 16nm feature size. If they can get to competitive sizes, then of course data centers will purchase it.