Fantastic thought. Though I think economic signaling theory shows the bottoms-up motivator.

Certainly in the US, the GI Bill lead to a decreased value for high school diplomas for the median graduate. This doesn't mean it wasn't the right idea for the time, just that it's caused a lot of crowding out. I feel like the Elite Overproduction is a good post hoc descriptive theory but missing the why.

Overproduction is relative to the system under consideration. If you set up a system in a certain way, almost all labor can be overproduced.

To take an extreme rhetorical example: if slavery is allowed, human capitol becomes ridiculously cheap and you can say labor is overproduced.