The answer is “maybe” and really depends on if Oda fucks up the ending or not. A good/interesting ending could keep me logging in as long as discussions go on, but a bad ending, depending on how bad it is may cause me to lose interest.
We do have Kingdom to keep me interested but we may need to create a Kingdom Discord server in the event that WorstGen shuts down or whatever, because Kingdom alone will not keep a One Piece forum alive in the event that Oda screws up the ending to OP, lol.