That doesn't mean TikTok would be able to continue operating, but it could mean the parties involved wouldn't have to suffer penalties for their operation up to that point (past the ban date). But maybe it wouldn't work, and a judge/jury would throw the book at them. We just don't know until and unless it goes to court.
If you're arguing that qualified immunity would enable Trump to break the contract if he so chose without consequence, then that is probably true, but I see no reason that would imperil the companies having a rock solid defense against enforcement penalties in the interim period.
Companies => Agree to temporarily facilitate the operation of TikTok until matters are further clarified.
I don't see anything particularly controversial here.