Regis Philbin (Who is now 85 by the way! Wow!) says he was never invited back to Live with Kelly, but Access Hollywood did their research, and showed video of him backstage in 2015 for their Halloween show!
The President & General Manager at WABC, where the show is produced, spoke out as well saying that Regis was invited to be a guest, and didn't make it for his appearance.
He also said he felt Kelly was offended when he left the show.