No, it's not collusion to ask for more money from OpenAI if you hear that they are trying to buy 40% of the world's supply. Increased demand leads to higher prices, that's normal.
OpenAI, by doing simultaneous deals, hid the true demand from the suppliers, thus lowering their price and raising everyone else's.
What?? Replace DRAM with peaches or table legs and you have the exact example they give you during management training to explain implicit collusion.
A case could be made though that it is OpenAI who is operating illegally, attempting to corner the market.