Tim, if that were the scenario, although extremely unlikely, it might be closer to the case. After all, Nicholas did abdicate on his own terms, as it were. He did a doubtful abdication for his son as well as himself, did he not ?
As Michael declined the throne, under the circumstances, that was the effective end of the monarchy.
These "what ifs" can go on forever, in many directions and I am not immune from having my own as well, but, as it is, they are just imagination, are they not ?