Sorry, I don't buy it. Was anything happening in FPH illegal? If not, then there's no rational basis for treating it any differently than any other hate-oriented subreddit.
If there were in fact some legal concerns, then I stand corrected.
Reddits stated policy was to remove harassment (and harrassing subs). So fph harrassed users and broke that policy. Coontown, while also racist and imo worse, stays in its box, doesn't brigade, doesn't target specific people, and generally just says racist stuff about news articles and posts memes.
If there were in fact some legal concerns, then I stand corrected.