As others have said, as long as this doesn’t change the behavior of locally removing or hiding other Player objects (essentially allowing a developer to hide themselves or anyone else from the playerlist), then I see no issue.
I also agree with what others have suggested about a proper built-in way to hide a player from the playerlist. Now I’m not sure that we need an Incognito Mode. But it would, at the very least, be nice to have a proper way to hide players from the client completely (preferably so exploiters also wouldn’t be able to tell the difference). It would also be nice, for that same function, to include a default behavior (perhaps globally or per-player). This way a specified user or perhaps all players join invisibly without even alerting a client that they have connected, until a method is called on the server to reveal them. Then once revealed or made hidden, it would trigger PlayerAdded/Removed events on all other clients.
The above is essentially already possible with the current behavior, all except for hiding by default (because a client would be able to detect a player joining even if they’re immediately destroyed or moved to a different location) and also making it look like the player disconnected rather than anything else.