There were a lot of big words in this chapter and I don’t think I did it justice; sorry if I got anything wrong.

The Cui family is, in fact, real. It’s no wonder that Li Bing had questions - the Cui family was very well-known, and there were quite a few Grand Councilors (it’s not actually an official title; just someone who has the highest administrative power in the dynasty) from that family during the Tang era. Actually, one Cui Xuanwei will even become a Grand Councilor during Wu Zetian’s reign - but that won’t be until 703. I couldn’t find any mentions of the family being involved in any rebellions around the time of the story, so that might be pure fiction. The other possibility is that only one particular branch of the family suffered - there were at least six main ones.

Also random observation - you might notice that Cui Bei is the only non-foreigner who has short hair (it’s not so obvious on, say, Chen Shi or Wang Qi, but we sometimes catch glimpses of the buns they wear under their caps). Since it’s against customs of that time, I’m pretty sure that Cui Bei’s hair suffered in one of the many accidents that happen around him…