lets try proof by exhaustion:

in those jurisdictions where either price discrimination or locking hardware are not illegal, it is typically perfectly legal to reverse engineer for compatibility purposes. So nothing prevents such resellers from upping their game and learning a thing or two about link training and general SDRAM bringup.

Once they have acquired the knowledge legally in such jurisdictions the product just flows in the other jurisdictions anyway.

Courts upheld the monopolistic position of microsoft etc. for decades, but respect has no finality, "re" + "spect" to review, so later such companies were fined for their decades long transgressions.

But during those decades it may appear legal to the average consumer.

Inaction is not permission.