I would love to see some kind of identity and reputation system where the "high-fives in the form of rep" could follow people across communities. It may not feel like much compensation if you've contributed over 2500 answers, but having reputation gained in your area of expertise grant you a high level of trust to interact in other communities could be valuable, at least in my opinion.
Assuming they're making this move to protect against AI / LLMs, I think SO is in an impossible situation here. When all the ChatGPT hype started, one of my first questions was "what happens to the incentive for contributors and creators?" Why would I want to contribute on a platform if I know an AI model is going to come in, take my contribution, and regurgitate it back to the masses in a way that I can't control?
Even if I get some attribution from the AI/LLM, do I even want it? If the LLM is blending content from multiple sources, which changes the context and presentation I put effort into, is the quality going to be high enough to match what I strive to achieve for myself when I'm trying to build a reputation as a high quality contributor? What if the AI is hallucinating objectively poor quality content and giving me partial attribution?
So, for me, part of the social contract with SO is that I provide answers, but I get to control the entire interaction; the context, the presentation (mark up), defending criticism in the comments, etc.. In addition to that, since the entire conversation happens inline, I can be corrected by someone even more knowledgeable than me and use that feedback for self improvement.
I think AI is going to be disruptive and the whole idea, for me anyway, behind disruption is that you break an existing system and then everyone is free to take a shot at claiming part of the new gold rush that occurs while trying to build the replacement. The problem with AI is that it's going to break a lot of services that do a good job of serving the community and shouldn't be broken. SO is a great example of a healthy community that doesn't need disruption, but the massive amount of high quality, curated content is going to make them a prime target for LLM training.
Personally I think the only solution is for "noai" variants of popular open source licenses so contributors have the ability to make it clear they don't want to contribute to AI/LLM companies. If SO had an option to flag contributions as CC-BY-SA-NOAI, I'd enable it on my stuff going forward.