I think there's an element to this and that's why I think it's a good idea to keep the sanction on Rubio. That way Rubio can't visit China and instead they will need to ask Musk to go (and he can always do it under the guise of visiting his factory in Shanghai if a cover is needed). Musk can then do closed door diplomacy Nixon style.
It's not clear if Trump and Musk are really such good friends that Trump would view this arrangement positively, but I'm very sure Musk would enjoy being the new Kissinger.
It also has the benefit of sowing discord among the new administration as Rubio would surely see this as Musk elbowing in on his turf.
Maybe Marco will become a scape goat and May Musk will be selected as a replacement.

