You hit the nail on the head in your post—these are things _you_ consider foundational knowledge.

I graduated with my Bachelors in CS in 2016, and those classes were optional senior electives. You were required to take a certain number as well as some required ones (i.e., Computer Architecture, Analysis of Algorithms). I chose to take Database Systems, Data Mining & Machine Learning, Robotics, Computer Vision, etc. as electives but not Concurrent Programming or Network Programming because I already felt comfortable with those topics. Others chose classes in topics like mobile application programming or programming language theory.

Those topics may be foundational for you, but not for others.