No, A.I. isn't being used to create a fake John Lennon vocal for use in a new track to be released by the Beatles later this year. As Sean Lennon took the trouble to tweet the other day, the tech was merely used to clean up an existing vocal by John:
Paul McCartney on June 13 mentioned there were plans to release a new track credited to the Beatles this year featuring a John vocal that had been extracted from a demo and cleaned up with A.I.
It's presumed that the vocal comes from John's demo for the song "Now and Then," which Paul, George and Ringo worked with during the Anthology sessions that produced the latter-Beatles tracks "Free as a Bird" and "Real Love." The quality of the "Now and Then" demo was more problematic and George Harrison reportedly didn't like the Threetles' attempts to update it, so the song was scrapped.
Now, with improved technology, John's vocal can more easily be lifted from the original demo and used as part of a new recording, which is exactly what Paul said, but many people immediately zeroed in on the A.I. part of the comment and started making wild assumptions about how the technology was being used. Maybe Sean's comments will help settle people down a bit.