hockeman18'smom

We're on Uniworld's European Holiday Markets cruise 12/1 - 12/8 on S.S. Beatrice and just received an email about this. I was confused, as our last river cruise was on Uniworld in 2019 and we had no "theme" nights at all. Just wondering, for those who've experienced this - did people dress more early 1970's (hippy style) or mid-to late 70's disco style? Thanks in advance!