In all but the most liberal districts, and maybe even then depending on how cynical you are, I think I'd expect any of that to get a pass as long as plausible deniability existed. Unfortunately, that's plausible deniability from the standpoint of parents and administrators who generally aren't statistically literate nor inclined to take student impressions all that seriously, and that leaves quite a bit of leeway as long as the teacher in question is bright enough to couch their objections in the right terms.

You know and I know that if the bell curve on expected achievement is shaped such that 30% of the student population from some minority group should be admitted to an advanced math class, and 0% actually is, then after a couple of years that's as good as admitting racial prejudice. But I think that'd be a much harder sell to a review board, especially one that doesn't want to incur the wrath of the teachers' union or any further investigative costs.