You seem to be adding a lot of intentionality to price swings that seem expected when supply is relatively fixed while demand fluctuates. (Maybe you’re right, but it’s not the simpler explanation.)
The supply isn't fixed. A new plant takes 3-5 years to build and cost tens of billions. DRAM companies don't always know where the demand will be when the next plant completes. 2 years ago there was too much supply so DRAM price hit rock bottom. So DRAM companies held back on investing in new plants so here we are now.
All three of those companies were convicted in a price fixing scandal.
I feel like it's "obvious" that it's not particularly in the interests of these companies to increase production in the current environment. Except perhaps in the long term "we don't want to get nationalized" or something, I suppose.
Personally I do not think think that they are dragging their feet extremely intentionally, but I do think they are structurally incentivised to do so.