The Atlantic: As Humanities Majors Decline, Colleges Try to Hype Up Their Programs

https://www.theatlantic.com/education/archive/2018/11/colleges-studying-humanities-promotion/574621/

Or did they just think (probably correctly) that their chances of acceptance would be higher if they selected humanities on their applications?

We’ve seen some colleges in the US doing just that for some of the most popular majors (such as CS). Will the practice spread?

A common belief, based on postings here. But changing into a more popular major after enrolling may be difficult, because the popular major may be full.

But also, as the prospect of having to find a job gets closer, any academic idealism that a high school senior may have could get deprioritized compared to preprofessional considerations.

The entire California State University system does that, although students can optionally apply or be admitted undeclared. Changing or declaring major is not guaranteed if the new major is impacted (enrolled to its capacity).

The Universities of California do that for some, but not all, campuses, divisions, and majors.

University of Washington and UIUC are other schools where one applies to the major as frosh. Applicants may get in undeclared, but many majors have restricted or competitive admission after enrolling undeclared.