Outside of the violence in the movie, some of Universal's motivation to pull the release likely was that it could have gotten hit hard on social media by Trump or his supporters. Why? Because there are certain lines that could spark anger from him and his base.
In the script, a group text thread among the elites includes one writing, "Did anyone see what our ratf---er in chief just did?" One answers, "At least the hunt's coming up. Nothing better than going out to The Manor and slaughtering a dozen deplorables." In another version of the script, that line ends "slaughtering a dozen inbred rednecks."
And in another scene in the script, before an elite kills someone, the person says to their victim, "For the record ... climate change is real."
In the US' charged political climate, it's safe to say lines like these would have caused a stir.