The graph suggests the gender balance was almost exactly 50/50 from 2019 to 2022. I very much doubt the gender balance just happened to land on exactly 50% male / 50% female. CS and tech balance is almost never 50/50 without some kind of admission or application preference. For example, 27% of students at GeorgiaTech school of computing are female. 30% of prospective CS majors in the Harvard freshman survey were female. Stanford is not much higher in spite of making special efforts to increase CS enrollment. Across all colleges in the US (NCES), the balance is ~21% female / ~79% male. CMU’s 50/50 was the exception, rather than rule.
CMU CS went from 31% female to 50% female in 2 years between 2015 and 2017, then % female enrollment started to decline after 2022. I expect CMU reduced the degree of admission or application preference for women, perhaps eliminating altogether. Lingering effects of COVID may contribute to the apparent changes in admission priorities.