The safest and most effective way to prevent Meta from destroying ActivityPub is to never give them so much as an inch. They WILL embrace, extend, extinguish if given the chance. Defederate from ALL Meta-owned instances. Be vocal about it. Tell other instances to do the same.
My heart aches for all the citizens living in Russia who have to live in fear because they're ruled by a tyrant dictator. If this news is true, things will only get worse for them. I hope the people can escape, or better: live in a better Russia with leaders who treat them like human beings.
It's wishful thinking, I know. Please stay strong, my Russian friends! Justice will be served one day!