Also since @screaming-bisexually 's question wasn't answered I think, lemme just go ahead:
That term has nor ever will be reclaimed, as it seems as of now.
It was still being used in german history books up until the 80's and after that was referred to as "Novemberpogrome 1938" or just "Novemberpogrom".
(Pogrom: A pogrom is a violent riot incited with the aim of massacring or expelling an ethnic or religious group, particularly Jews.)
The word "Kristallnacht" doesn't stem from Nazi Propaganda per se, it was more of a circulating word that got popular by word-of-mouth, no matter what political stance one was from.
(The jewish victims who got put into KZ's and never got to hear their neighbours talk about it called it "Rath-Aktion" or "Mordwoche" at the time.)
Kristallnacht translates to "Crystal Night" and refers to the shattered windows from jewish shops and synagogues, as well as jewish houses which the Nazis stormed into, smashing mirrors, windows and pictureframes.
Thus leaving behind a trail of shattered glass, "glittering like crystal" in the sunlight of the next morning.
That last sentence sounds beautiful, huh? That's the problem with it. That is why that term is so frowned upon. Because nothing about this was even remotely beautiful. It was a slaughter, a brutal dark moment in human history, and no words can describe how horrible it was.
"On record" the term Reichskristallnacht was first used by NS General Wilhelm Börger (NS = Nationalsozialismus = Nazi), who used it jokingly in a speech talking about the happenings of that day, with his audience laughing about it. He also added the Reichs to the Kristallnacht, to sprinkle that extra bit of fascism to it. Which just puts even more depth to why that term is so... not okay.
Right now, January 2022, the term how to call that awful day is still being discussed widely by politicians, historians and first and foremost the german-speaking jewish community, with Novemberpogrom being the "correct" one as of now.
But: It is important to keep in mind that someone outside of german-speaking countries who still uses Kristallnacht as a name for that horrible day is most likely not fascist, and doesn't mean harm in any way. Most likely it just means that their history books/lectures/etc. haven't been updated, or the subject wasn't covered enough for someone in a non-german country to immediately realise why it's wrong to use that word (Understandable, german looks like a letter salad to non-native speakers).
Here's my personal opinion though: If you know the history of that term and you still use it, you fucked up. Big time.
