I am not a lawyer, but the lawsuit not only makes no sense, but has outside evidence invalidating it:
1. The argument is essentially that HBM production has raised consumer DRAM prices to the point that _somebody_ should have swapped back to consumer DRAM.
A) It provides no _actual_ evidence that the profit margin on HBM is now smaller than even the elevated DRAM prices - and keep in mind, even if this were true, the relative margins on consumer DRAM would also have to cover the cost of retooling lines to consumer DRAM.
B) The relative margins DO NOT MATTER if the memory manufacturers already have their capacity booked. It does not matter if consumer DRAM has higher margins, if they cannot swap from _whatever capacity they currently have allocated_ without being sued for breach of contract with the companies they already have contracts with (whether that be for HBM or consumer DRAM).
2. The gold rush in margins resulted in previously small players like Chinese CXMT getting sufficient investment to start producing modern (albeit mostly lower end) memory chips. And they've announced... that not only is the increased capacity going heavily to HBM, but others companies are already booking any remaining capacity, signing contracts with Tencent and Apple (for Chinese market products) in the last few weeks.
Or to summarize, an outside party is also pivoting to HBM, which establishes that the big three's decision to stick with HBM is not anti-competitive, while also having all their capacity booked, which reinforces that the big three largely cannot swap as they are are contracually maxed.
3. I know both Micron and Samsung at least are attempting to push up the launch of additional memory fabs.. and they're both HBM focused, as that is still where the unfulfilled demand is, which again invalidates the entire lawsuit.
To be clear, the memory industry has had a long history of price / capacity fixing - when there's only three players and a handful of fabs, onky one extra fab leads to oversupply leads to price collapses. But there's very little evidence of that here - it's just a rare (if not unprecedented) scenario where there is a massive overnight demand for a difficult to produce item, and said purchasers are willing to pay a premium to acquire that capacity over all other buyers.