Of course a sane president could work from any functional office, but that would apply to the current president too, if he were sane, and the office he inherited was functional. It is customary for a new president to redecorate to taste, but if, as some might opine, the current demented rapist-in-chief has defaced the office so greatly that it becomes a symbol of his fascist folly, and an embarrassment to a rational person, it might well behoove a successor to step out of the office while it is restored to something reasonably consonant with presidential dignity and function. Especially if, as is quite possible, the only scenario in which a non-cult successor might be in such a position would be after a dramatic event such as a coup or and uprising. Of course it shouldn't take too long to get the office back to normal, but I could imagine that it would be easier to work without the distraction of workers and power tools and whatnot.