Absolutely impossible. There's just no way a betting establishment would want this. How can you know the script and then set spreads?
MY guess is in theory, only a limited number of WWE employees and their independent contractors (ie the wrestlers) would know the script (and based on the article, the wrestlers would only know the results hours ahead of time).
Meanwhile the Betting places would not know the script and would set the betting lines.
I think it could work, I just think it's an absolute horrible idea... as I think they'll be more likely to have people try to cheat the system as results will in theory be known by a few and wrestling can have people mentally struggling and stay in the game a lot time, where in professional sports the competitive nature usually takes out those that are mentally struggling.
Also if you get thrown out of your major sport league, there usually isn't a decent second option.
In theory with wrestling there are other major pro wrestling companies (that don't quite pay as well, but I don't think they're nearly as far behind as the backup to NFL, NBA etc leagues).
So they could just go to AEW or New Japan... if kicked out of the WWE.
And I believe UFC just had a scandal where one of the coaches, or guys in a coaching corner was putting some big bets on fights.