The first Ponies The Anthology featured a content warning and even a separate clean version, while the second one was specifically designed to stay within a PG-13 level. Word of God from one of the Anthology's contributors is that this actually made them think more about what was funny versus Vulgar Humor.
In the AU Slightly Altered despite having some truly horrific moments, is still a LOT lighter in tone than the original series. As of Chapter 8, nobody apart from Buwaro's biological parents has died, not even Sakido. Rhea is oddly absent, though, so she may be dead.