I think possibly. I never use anything in front of a plastic BUT look at some of the lures that catch bass- many are not very natural. Some depends on how hungry the fish is.? Who hasn`t had a bass hit the bobber on a crappie rig? Sometimes they seem really smart-sometimes not.
Best reason to use a swivel would be line twist but if plastics are rigged right it shouldn`t spin.
I use snap swivels all the time, it makes changing lures a breeze. When I accidentally throw a lure over a tree branch and it comes through down to the water, I unhook them and them bring my line through the branches, it save me lots of time, lures and money. As was mentioned by Mookie use good quality swivels. These a great swivels $2.99 for 5 in size 0.
Once in awhile the swivel will foul a treble hook but the pros outweigh the cons to me, I use these even when I throw grubs.