As I figured, the records concerning Black Oscar nominees were demolished this year, see e.g. the Wikipedia page for all the Black nominees.
This year had by far the most Black Oscar nominees in a single year, with 18. The previous record was 8, back in 2006, followed by 1985 and 2009 with 7 each.
This year also saw most Blacks nominated in a single category (5 in Feature Documentary), most Black acting nominees, most Black acting nominees in a single category and the first year there was a Black nominee in each acting category.
Among other trivia (If I'm wrong, I'm sure someone here will be happy to correct me):
Denis Villeneuve is the first French Canadian to be nominated for Best Director.
I believe Raoul and Hébert Peck are the first Haitian-born Oscar nominees.
I believe Daphne Matziriaki is the first Greek-born Documentary nominee. She is nominated against Dan Krauss, who taught her at Berkeley.
I believe Sing is the first Hungarian film to be nominated in the Live Action Short category.
And here's one that's likely to happen: Damien Chazelle had his 32nd birthday a week ago, so if he wins Best Director, he'll beat Norman Taurog to become the youngest person ever to win that category.
Ai-Ling Lee is the first Asian to receive a nomination for Sound Editing and the first woman to receive nominations in both Sound categories. La La Land's Sound Editing nomination is also the first time two women have shared a nomination in this category.