@1Wife1Kid Other languages may be going through the same thing (ex. for Spanish: Latin@, Latinx, use of “e” instead of “o” or “a” on adjectives) – it’s not purely an American issue. Presumably if a nonbinary person goes to a culture where no such change is happening, they (look! singular they!) will figure something out. I don’t know enough about other languages to know if they have a similar usage to “they” – something colloquial that people use when gender is unknown, though it may not be in the dictionary that way. Either the student will create something, use existing alternative structures, or pick whichever usual pronoun in that language they can stomach. That’s as complete of an answer as I can construct, given the fact that I am and have always felt female. 
As far as big vs small issues: hence, intersectionality! People can care about more than one thing at once. I can be upset by the proposed pit bull ban in Montreal at the same time as I am upset about sexism. Both are important to me and I spend time advocating against both.
Edited to add, in case you meant “How will they cope?” in a more general sense:
Probably similarly to how they do at home. Cooperate to be polite until they morally/emotionally can’t anymore. At least that’s how I’d do it.