I suspect it might tie into the whole concept of the Doctor doing a wibbly-wobbly fucky-wucky at the edge of the universe and accidentally softening the borders of reality and fantasy. I don't know if it's going to be all She-Hulk and end with the Doctor meeting RTD in his office, but I think something is in the offing more than just a stylistic flourish.
I think that's reading too much into it. There's been no more fourth-wall breaking this season so far than there was in Capaldi's run, and it didn't build to anything there.
Fourth-wall breaking is simply a comedy technique, a wink to the audience that it's all in good fun. It's clear that RTD is prioritizing fun and whimsy this time around, at least so far, and there's no reason to think it means anything more than that.