Been intermittently watching through the weekly WWF shows from 1990. It appears that Jesse Ventura's moment of disappearance was the August 25, 1990 show. Piper scoots in as the new commentator. The end of Jesse on commentary was truly unfortunate; we would never again hear top-tier heel commentary that wasn't primarily comedic.
The notion of Rick Rude winning the WWF Title at SummerSlam '90 never felt remotely credible to me, and it still just plays to me as a cold program watching it back. There was kayfabe sense to it given WrestleMania V and all, but I just don't think it worked at all.