I do believe that most insiders had an early version of the album for months, tho. It would explain why Thunder and Dealer sound unfinished (even in low quality, you can hear they're not properly mastered...) And similar to BOZ's Arcadia description (although he has always been a little off describing things )
It makes sense why no one has teased/leaked BBS, if it truly was recently added or why the album hasn't leaked at all, since they probably don't have the whole thing
If they don't leak the demos/early version, then I guess we really won't have a leak until someone gets a copy (which seems unlikely as they're getting shipped either the same day or days later)