I was asked, along with my fellow band directors, to a CDL many years ago (very small school - bus drivers were in short supply). Took the training then...none of us ever went and took the test. The principal asked us several times throughout the year to go take the test, but we never did. Then the principal got non-renewed and we never heard about it again.

Asking band directors or coaches to teach a full workday, then drive a bus/monitor kids, then work the football game/marching contest, then drive the bus/monitor kids on the way back is, in my opinion, both unsafe and unethical. I would absolutely resign if it admin was forcing a CDL.