Obviously Sergachev was an unknown commodity at the time given that he hadn't played in the NHL yet, but it'd be a pretty huge disaster (moreso than it is already) to move Drouin for what he'd return right now. I don't think he'd bring back anything worth a damn right now, TBH. Best bet is to just try and suround him with talent, keep him on the wing and hope he regains some of what he was able to show in TB from time to time.
He's definitely never (IMO) going to live up to his hype at this point, but I still think he can be a consistent 20G/40-50P guy if he's given proper linemates.