Yup.
I started to hear that during season 4, but I’m not sure if Sunset Shimmer in the TV show would be the right move for the show. That’s probably why we had Starlight Glimmer in season 5, an answer to the petition of “putting Sunset Shimmer in the show”, an equivalent (I know they’re not the same character, but it’s essentially the same core idea, especially the Sunset Shimmer from the first EG film).
Personally, I don’t think the idea of a character being in a show should be good just because “thousands of people asked for it”. By that logic, every single Star Wars film would have Boba Fett. I’m more into new things and new characters. In fact, the only MLP character I wanted her to come back was Chrysalis, and her presence in seasons 6, 8 and 9 were very underwhelming. For a TV show filled with some unnecessary returns such as Iron Will, Glim Glam brothers and Trixie, I’m amazed that the writers didn’t take the chance to apply the same dedication with a villain that had so much potential until it was too late.
But at least I have the fanarts and fanfics.