I noticed that any user could create an invite for a channel, even if they are not a channel member themselves or even have access to the channel. It doesn’t matter if it’s a [spacer] channel or a password protected channel.
But since the Invite function only works poorly anyway, this is not that bad, because you connect in the default channel anyway.
My question would be, if it is not possible, that users could only create an invitelink for channels they would have access to, otherwise it is very confusing.
At least then should come similar to TS3 a notification that the client does not know the password.
In TS5 you can of course create a generated link again without any note.
In conclusion, I think that the invitation function for channels to which access is not granted should be removed, otherwise it is unnecessary.