FSF leadership is currently having a crisis since, due to recent events, they realized that Stallman is not eternal. FSF-owned code is an incredible asset. If there were a corporate takeover of the FSF, that could have very bad outcomes.
Regarding contacting every owner, that'd be a nightmare in 1960. In 2022: "We will contact you at the email address on file," an ability to opt in / opt out via web form, and some language about changing to equivalent media (e.g. SMS, fax, robocall, USPS, AOL Instant Messenger, or whatever).
I'll mention I picked out a few examples of nasty legal language. The whole agreement is nasty, unfair, and one-sided. I like the concept a lot, but I'd never sign language like that. I like working with organizations who try to be fair to both sides.
Oh -- and for language which applies to "successors" -- all bets are off. I specifically do not want the SFC to assign my copyright to a successor. I've seen specific examples where a successor to a non-profit was a for-profit.