I’ve said it a long time ago. The ActivityPub WG at W3C must spring into action NOW and prepare itself for the big corporations that will try to overtake the standard. The core members should make sure that transparency and openness is turned to 11. No backroom dealings. A very clear IP policy that requires royalty free etc.
The original WG was https://www.w3.org/wiki/Socialwg which is officially inactive. It could be revived by community members, before the big companies decide to start a new one themselves. Which WILL happen.
Watch out for proprietary "extensions" and "creative" interpretations of the standard that will limit interoperability. This is already happening. It's a pity that there is still no official validator for #ActivityPub that could help with mitigating this.