>>51363158I still believe she is. Or rather, was.
She was portrayed as a villain in the anime and manga, but even in the games, she was originally designed to match the Team Rocket using whips to control her Pokémon. You have to ask, why was literally every portrayal of her in Gen 1 some kind of villain/darker than other Gym Leaders? It can't be a coincidence. She was clearly designed to be a darker character.
The context of later games showing Gym Leaders actively concerned or even fighting off Grunts that show up in their city makes Sabrina's indifference to Saffron's takeover much more notable. Especially when we already saw her capabilities with the Fighting Dojo essentially being a ruined, run down Ex-Gym. Visual worldbuilding about how a powerful Gym Leader shapes her environment, yet she does nothing when a bunch of Grunts with poison Pokémon take over Silph Co.?
And of all the Kanto Gym Leaders, she was by far the most drastic re-design. If you showed the FRLG art to anybody, and followed it with the HGSS art, the obvious assumption would be "oh, they used to be bad but had a change of heart?"
I think this is even more notable when you consider she is one of the only returning Gym Leaders in Gen 5 (outside of the PWT) and she is now an actress. Why make such a point of showing her in a new non-Gym position/lifestyle if it wasn't also to contribute to the development of her character? That abandoning her darker, stoic persona allowed her to pursue her more honest dreams?
TL;DR - My headcanon/theory is that Sabrina, even in the games, was at best indifferent to Team Rocket, at worst actively a part of them, but completely changed her ways and image after they fell, hence the shift in black to white in her clothing, thus able to pursue a career in acting.
Also a bonus, her EX outfit (which typically take the colors of the Pokémon the character uses, but there are exceptions, such as this case:) in Pokémon Masters appears to take Team Rocket colors.
