We fly out of FCO on May 28th. Our flight was scheduled to leave from Terminal 3 and I confirmed the flight that morning. After having the town car drop us off at T3, we were informed that we were flying out of T5. We had to catch the shuttle bus, as did all the other people on the shuttle. T3 smelled of smoke and all of the workers were wearing face masks.
If you are scheduled to fly out of T3, make sure to give yourself a lot of extra time to change terminals.