Ironically my own HS curriculum had us both read
The Adventures of Tom Sawyer and watch
Gone With the Wind precisely
because of their racist content (that is, as a way of understanding and critiquing racism in everyday culture).
I can totally understand bringing TKAM down a few notches in the canon, and bringing some of the many, many neglected works by authors of color to the fore. But even the thought of outright banning from the curriculum would have been seen as quite regressive indeed, at the time.
It's ironic to think "how far" we've come since then.