No, the character's appearance has been changed to line 261 instead of whatever it was before. appearance.2da hasn't been changed at all.
I wouldn't expect so. The game doesn't spontaneously change your appearance once it's set. It isn't supposed to, anyway.
I took a look at a player file when equipped with a Sand Person disguise. Appearance_Type does change, but there are some other properties further down: PM_Appearance and PM_IsDisguised. It looks like those entries save information about the player's original appearance. So it could be something going wrong there instead.