I personally don't know anything about Cara, just the typical situation of people panicking about a social media and going somewhere else.
I thought people went to Bluesky for the same reason when Elon Musk bought Twitter.
Honestly, I don't think the Meta AI is going to be implemented properly, as Instagram and facebook are also very well filled with memes and reposts with tacky watermarks. Besides the downgrade in posting quality especially when you see Instagram posts from PC. There is Glaze and Nightshade too, so I believe if someone is really that threatened, popular or worried, they could do poison their works before posting them so its useless for AI scrapping.
I don't think my art is that great to be fed to AI, so I won't change socials just yet. I think I have enough in my plate with FB, Insta, X, Tumblr, TikTok, Youtube, Ko-Fi and some Discord Servers. I do have a Reddit and Bluesky, but they have the least activity on my part.