The real story is that in the US, we are politically polarized enough to buy into the dean's story that this is the only reason for the suspension.
Universities are run as businesses nowadays and I can assure you that they don't care about angry students unless there is money or prestige to be made in appeasing them. At a past university I attended, class enrollment was horribly broken causing people to miss out on courses they needed to graduate. Basically the whole student body was mad and made it known and sent around petitions, but nothing changed. The fix being pushed by students would literally just require changing a config file somewhere and sending some emails, but nobody cared.
If universities won't lift a finger for issues that cause campus wide outrage, why would I believe that they'd suspend someone after a twitter minority gets unreasonably angry about something like this. I'm at one of the super liberal universities in the US and I can promise you that it really is a minority. Even in the liberal arts classes I've attended, everyone I've met would be like "yeah, that's an unfortunate mistake and at most you should probably just inform him that the word sounds like a slur". I have literally never met someone that would call for a firing except for on twitter. I've also taught classes here and never met one, so I know it isn't a selection effect where I'm in a bubble. I don't get to choose the students I teach.
There is 100% more going on than what the dean is claiming. Maybe it's administrative drama. Maybe the professor wasn't pulling in enough grant money. Maybe the university was eyeing his salary and knew about an adjunct that will do it cheaper and thought that this would be a nice excuse to make a change. From everything I know about universities and from currently working at one, the guy didn't get fired for something as outlandish as saying a word that sounded like something else. It just doesn't make sense.