If it doesn't at first, you can bet it will eventually. Don't take the chance of something being significantly damaged. A reputable camera shop should be able to help you.
I had a 120 film back recently (forget which one) and a part just like that fell out too. I looked it over and found where it came from. It was held in by two metal tabs and the pins on each end of the part fit into holes in the tabs but the tabs had spread out a bit allowing the part to fall out. I just put it back and pinched the two tabs together a little and all was fine again.