Wow, this seems like an incredibly stupid business decision on the part of Choice.
Since the difference between a general member and a Diamond elite (or even any elite level really) is so minimal, I will stop reaching my Diamond elite status going forward, and moving most of my discretionary stays back to other hotel chains.
I expect I'll drop from Diamond elite to a general member (or Gold elite at best) next year and going forward, a loss to Choice of 30+ nights per year.