And then -- I can't figure out what you're talking about. I have no problems listening to any Beatles albums in Stereo. They're perhaps wider stereo soundstages than you'd find today (where albums mostly play the same GD thing out of both channels) -- but that makes them sonically interesting, not unlistenable.
I think what is being referenced is what used to be called "ping-pong stereo," the very wide and complete separation of channels -- which in the Beatles catalog is heard mainly on the Rubber Soul and Revolver albums, the two best they ever made IMO. I'm not a huge Beatles fan, but mess with these recordings at your peril!