A thought I just had: Maybe there’s actually more songs with vocals than we realize, and the six or so they worked on during Covid are just the ones they’re planning to release “for now.” If it is true that some songs are being saved for later, that would explain why there’s been no sign of atlas. You’d think that woulda been the first one out the gate, but maybe Axl wants to save it for a more “meaningful” project.
Another possibility is that, if there are other songs with vocals, most of them are probably just “scratch tracks” like State of Grace, Nothing, Quick Song, etc., and therefore unusable.