That may have been less Lucas “trying to convince” Spielberg to re-do Jaws and more of him idly musing about that being a possibility with the advances in CGI that were happening. That anecdote is third-hand, after all.
True, it is a third hand anecdote. But after all, we all know what happened in 2002 with “some other” Spielberg movie…
So maybe there is a small amount of truth in that story 😉