I'd be absolutely astonished if Hogan no-showed, however it might not be as whacky an idea as it first comes across, Hulk Hogan is all about himself, he thinks he is still a big deal, he probably is, well to many older WWE fans anyway, however is he banking on those guys being the ones who tune in to TNA?
He might feel that if he loses badly on the 4th that might be a resounding "You don't matter anymore" which is something that many people believe anyway, its conceivable from that aspect that he could possbly pull out, but for me I don't think its likely at all.
His name is linked to it now so people tuning in would be expected to see him, so I don't think it would reflect that rating as such, not unless it was revealed prior to the show that he wont be turning up