Well, they actually DO those things fairly often. Typically speaking, a heel takes a DQ finish to retain, and then the next match is booked with some sort of no-DQ stip to prevent it from happening again.
But not often enough. And most of the time they wait until the match is several minutes in before they do it. Why not kick them in the nuts straight away?
I could totally see a heel GM "pulling a Brodus" with a face's rematch clause though. "hmm, he's got a slight knee tweak, your rematch will have to wait until next week" *repeat a few times* "oh, your 30 days are up. Sorry. Here's a #1 contenders match!"
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