Here's some things to keep in mind:
Live action elements have been used in south park pretty much since the beginning.
We've seen hints of what this could look like in "i should have never gone ziplining" and even more so at the end of "grounded vindaloop"
Some of the most popular episodes have featured some change up with the animation style like in "good time with weapons" and "make love not warcraft"
They've got one of the best deepfake teams in the world. if you haven't seen it yet, watch "sassy justice" on youtube, al gore is super cereal!
I think that last point is super critical because of course you don't have to deepfake a celebrity. you could do it for a child actor who signs up for it. you might even superimpose, the possibly de-aged versions of, matt and trey's own faces onto an actor's body. the reason why you'd want to do that is because one of the most akward parts about going from animation to live action is that the voice of the actor doesn't match the voice of the character. with deepfakes, the kyle actor can have the actual kyle voice, the cartman actor can have cartman's voice, etc. you pretty much eliminate the risk of bad acting too because all the actor needs to do is move their body around, everything else is on post-production.
I personally can't think of a good reason not to do this for an episode or even a movie! but what do you guys think?
(possible spoilers past this point)
We know from an interview that matt did with bloomberg that they want to do a movie with their deepfake team: "We’re doing deep fakes. We have a studio with a dozen people who are deep fake artists. We’re working on a little more of this deep fake movie we’re trying to piece together". it's not guarenteed that this would be a south park movie, but when you're on the docket for 14 south park related movies! -it sounds alot like this could be one of them.
He also says "We have this idea where the first ones for Paramount+ are “South Park” but not quite. We have a high concept idea for the first one to set it apart." deepfakes = "high concept", live action = "south park but not quite". yes? no? maybe?