it won't hurt and it should help you rotate out that comb. as soon as the queen has started laying below or has moved more to the middle, you can start cutting out one frame at a time and replace.
when or if they swarm depends on lots of things. space is only one thing. some hives just swarm. keep a close eye on them for swarm cells. make a nuc from the old queen if you find them and they may feel that they swarmed. or...maybe not.... :-D