Aw. I think you have to put up with it for a little while, and they maybe start running into poorly placed furniture and complaining about the bad acoustics.
I'm impressed your H has any desire at all to move furniture on his own accord. Mine wouldn't ever think of that as a fun activity in his free time unless I tell him to help me.
Ha! I cringe at the thought of my DH trying to arrange a room. I cringe when he attempts to do any decorating. But what can you do it's their house too. Just suck it up for awhile and then slowly change things yourself.