>>577584983D outline doubles the model's polycount (well, there are other ways but they require to have above room-temperature IQ so no graphic programmer at GF can do it). Removing the outline allowed to put even less effort in optimizing the game. Smart move.
And the custom cel shading shader was probably made long ago by an intern (who got fired for actually knowing basic shit, a big no no at GF) and probably broke after an engine update, with no-one able to recreate its arcane mystery nor being able to follow a "my first cel-shading material with shadergraph" 3min tutorial on youtube, because there was some big technical words in it like "computer", which is way above the mental capacity of an average GF employee.
