I have noticed that "lvresize --help" shows a "-r|--resizefs" option, but looking for it in "man lvresize" doesn't show anything resembling "--resizefs". Hence, I'm not sure whether this option actually works, and I'm not brave enough to just try it. :)
It's incomplete - waiting for someone to finish writing the code and testing it. If you try using it, you'll just get an error.