There's a big difference between "I'm proud of my culture even if celebrating it is frowned upon" (this is as mild as I can make it in case I misconstrue his words since I'm not reading it first hand) and "My ethnic group should live a different (and presumably better) life separate from other ethnic groups" (again, as mild). It's funny that so many people bring up the right to free speech especially when that speech is meant to express views that wish to hurt others. I don't think anyone invoked the right to free speech when they expressed views wanting to help others. (unless of course they talk about helping the enemies of the US lol)
If I were you I'd anonymously send as much screenshots to your manager, FAA HR and some of the officials. Also to the liberal press for good measure.
There's pretty much no more difference between "job time" and "private time" anymore. Look at that woman in Central Park who got fired from her law firm for calling the police and lying that she was being choked by a black man because he asked her to put her dog on a leash.
Tech wipes out all privacy now. You can't be a shitty person in private anymore.