People generally don't incorporate in these circumstances until they need to. I've worked in plenty of processes where the binding bid document simply refers in general terms to 'a UK limited company, to be incorporated in due course' because it saves the hassle of setting one up and then closing it all back down again if the other conditions of the sale are not fulfilled.
I hear you, but I've also been in plenty of transactions were it's done a good bit in advance of closing, while contingencies are outstanding, because it's cheap and gets it marked off on the checklist, and people generally assume the deal's going to go through. Just sayin'. Hopefully, though, it will get done in the next few days.