Maybe he thinks he shouldn't spill the beans, but S31 would want to know about V'Ger, the Whale Probe, God, the destruction of Ceti Alpha 6, and the Borg--all things that would've happened or are out there regardless of the timeline changes.
No, probably not. And he will be focused on Vulcan so there's no obligation for him to disclose anything but he wouldn't withhold either.
Section 31 under Marcus is myopic then gutted by Khan. What they might be interested in from Spock was not something they focused on at all. And now they're dead.
Indeed, it would almost seem criminally negligent of Spock not to tell Starfleet about V'Ger and the Whale Probe, at least, given that they constitute existential threats.
Voyager demonstrated that quite clearly with Past Tense, as well as Relativity. Or, as Doc Brown might note something about the consequences.
When were these rules put in place? Old Spock showed up pre-TOS and that era Kirk and Spock aren't bound by rules not created by that time. And, again, since it's an alternate timeline, everything they do at that point is like you and me going through life right now.
Well, that isn't so much about "rules" as "don't say or do anything to disrupt the timeline." That's common sense, not a regulation. Kirk and Spock experienced it first hand in the original series when McCoy saved Edith Keeler.
Well, Spock left in the 24th century so some rules probably changed.
No my point was, McCoy changed history because he futzed with what was supposed to happen. You don't need a cell phone to change the course of history. But that wasn't a regulation. It was a general bit of common sense. "Don't step on the butterfly."
They also had time travelled multiple times so Spock was aware of possible consequences around major events.
