Here's why I wish they had a reunion - especially in the '80s and beyond.
Trying to imagine what kind of music the four of them together (and that's the key: together) trying to predict that would be like predicting Sgt Pepper after listening to With The Beatles. Or like predicting Abbey Road after listening to Magical Mystery Tour.
Everything they did together was totally unpredictable. So saying 'Beatles disco', presumes that they wouldn't have advanced a whole other musical style. A style that never emerged because of their absence.
The only answer is who knows - however, we can assume based on ...