#1. Should: Paul Heyman's betrayal doesn't mean a heel turn for him
Paul Heyman doesn't need to become a bigger heel by betraying The Tribal Chief. The biggest difference between the Roman Reigns-Brock Lesnar feud now and before is the fact that the dynamic and characters have shifted.
While WWE tried to use Lesnar as a monster heel to get Reigns over as a babyface, it simply didn't work - neither in 2015 nor in 2018. In 2021, however, Roman Reigns is the heel and Brock Lesnar is the babyface - a change seemingly welcomed by fans.
While we argued that Reigns shouldn't turn face anytime soon, he doesn't need to. Paul Heyman betraying him and joining Lesnar could be done in a way where the advocate and special counsel turns face instead.
It would be used to enhance The Beast Incarnate's status as a babyface and also Roman Reigns' status as a heel. Before that can happen, the tension needs to continue between Reigns and Heyman, with the former likely asking The Usos to take his special counsel out for good.