TIE Advanced Prototype.

You mean TIE Adv. Prototype.

Myeb

Because tie/x1 + ATC inq would break the game like a glass panel shot out of a cannon

The ship is canonically the tie advance v1, but in game it's the tie adv prototype (taps) to prevent it from taking the hilariously overpowered fix to a hilariously underpowered ship