Could be that US toolmakers are trying to get around the restrictions by establishing franchises and moving production to SE Asia, removing "US persons" from production, maintenance and even design. The problem would be parts and components but my guess maybe parts-materials producers can do the same or tools makers could avoid using US made parts or components by buying those in Asia and Europe.
That sounds like the spinoff approach ARM took with ARM China to handle all the activities at arm's length (no pun intended) without involving the parent company or the US in this case while the parent company just collects the money and sidesteps entanglements/politics that result from doing business. Logical solution to retain market access but since they didn't come out and announce it to the world like ARM did it's anyone's guess.
Are LAM, KLA, and AMAT getting licenses to sell or something? Also it's done through their SE Asia subsidiaries it seems.
Well, since as of right now there are no restrictions on what Japanese and European companies can sell to China, KLA/LAM/AMAT/etc are probably arguing in their license applications that denying them would just be throwing money away since the same/similar thing can be obtained from somebody else. It is up to export control officers to take these facts and the new rules into account when making determinations.
Anyways, the bottom line is that US companies will use every legal option available to them to stay in the game even if they have taken quiet a few punches to the face. No matter you package it, this is a middle finger to the US government.