I honestly don't see how this can be held as a confirmation it isn't happening, considering the amount of evidence that's been coming out the last few days. Perhaps Pete was oblivious to all of that when he said that?
Pete seems to be oblivious to most things, so this is possible.
What if the members of Fall Out Boy have no idea they're playing Kimmel next week and get tricked to fly out to Hollywood like in 90s sitcoms when one friend tries to get the other two to talk to each other.