Previously, client mods adding packet-sending scripts to the spawn area made clients send the associated packets as soon as they inputted their character name when joining a server using those mods. This made the clients either get disconnected for not replying to a handshake first, or it made them get kicked for sending object packets that are disallowed for players who are not logged in.
To fix this, LocalPlayer's hasFinishedCharGen() has been replaced with isLoggedIn(), because the former was already returning true when players inputted their names.