Yes, I think that's the best explanation - Sybok wasn't showing a literal event but rather an emotional perception of that event.I see it as Spock's perception of Sarek/Vulcan's attitude rather than an actual memory. One that Sybok sought to exploit, because when he left Vulcan that was Spock's mindset.
I don't remember - were there any Vulcans among Sybok's group? It's possible his Jedi mind tricks might not work on them.
BTW, I just found a contradition in the TFF script (shock horror):
SPOCK: He rejected his logical upbringing. He embraced the animal passions of our ancestors. ... When he encouraged others to follow him, he was banished from Vulcan, never to return.
But later...SPOCK: Sha Ka Ree - the reason Sybok left Vulcan.
So did he jump or was he pushed?