The Snyder Cut did get decent reviews when it finally came out and it seems like most of the reporting on the Batgirl cancelation so far as been direct observations of the fact (some OPs on it being a mistake, but still). Also, most of the negative press for the Snyder Cut came from the toxic online activities of the Snyder cult over the years demanding its release (from review bombing, bullying people online, using bot, and, allegedly, being manipulated by Snyder himself), whereas, so far, the "Release Batgirl" crowd hasn't exactly shown that level of vitriol yet. So, I don't see it as a direct comparison yet.
(Also, while I'm sure there will be clickbait on the subject, it so far seems like most of the backlash has come from "fans," so it seems safe to assume that what pushback there is is genuine. Course, I'm someone who was looking forward to the movie and am mad enough that I'll probably personally boycott anything that's part of Zaslav's so-called ten year plan, but I can only speak for myself.