I don't know, this feels like it's gearing up to be a celebration of Macca's career though so I'd expect something special.
But, I think Ringo is touring America while Glastonbury is on so I was completely wrong. ?
I have no insider knowledge or gossip, but I reckon you'll end up seeing two Beatles. There are usually surprise guests at Glastonbury shows and I bet McCartney brings Ringo out for at least a couple of songs.