Big deal, so the 'fellow' former band mates and producers kindly allowed Syd to carrying on performing as a studio soloist and wrote heartrending tear-filled tributes to him and even - gasp - let him share some royalties, which were his anyway.
The facts of Syd's departure are well-known He was treated horribly insofar as the way they dumped him, his having been the genius that put them on the road to superstardom anyway, with his innovative light slides and mirrored guitars. When he became catatonic on stage, they simply didn't bother to pick him up to attend gigs. He initially had no idea he had been frozen out. He'd turn up at recording sessions to their dismay, and they would mock him and joke about his pouring mandrax over his head, etc. When Syd realised he'd be ousted, it must have been a massive body blow to him and it can't have helped his mental health.