For one thing, I would consider SE changing drastically the licensing on MO data, or making restricted commercial profit out of it, to be a red line. In my opinion, MO data should remain free to access, to use and to cite (even for LLM training if it comes to that, I don't want to pinpoint a particular use-case as long as the licensing is respected). I know that SE management has already performed in the past years a re-licensing (An Update On Creative Commons Licensing) and are trying now to get money for the use of the network data as a training dataset (Is SE [going to be] selling our content for AI model training? And what exactly does "reinvest back into our communities" mean?).
I have very suspicious feelings regarding the latter action, since a lot of recent behaviors of SE top-brass management are far from being to my liking. But that's maybe another point altogether.
EDIT: as has pointed out by Emil in the comments, SE is now holding back the automated data dump: June 2023 Data Dump is missing. As a consequence, I revoked all my SE accounts. I keep my MO account since it is not a complete part of the network, but I'd like now to actively advocate for a referendum (as suggested by Timothy) regarding a SExit (if I may say so). I'm willing to go, I don't see why we should stay in a place where the makers of knowledge are bullied and trod upon by money sharks. There seems to be other networks run by old allies that could be a new home, although the "where" is partly besides the point.
I'm willing to contribute, financially and technically, in any reasonable measure that I can, but first we have to make our collective mind.