So we don’t want to use this, but there is no way to opt out and we still have to pay X extra per user :-/
(Disclaimer: Although I have worked for Google in the past, that ended almost a decade ago and wasn't in any role related to pricing or product decisions about Google Workspace. I have no inside info on this announcement and am not speaking for Google here.)
Opting out of the functionality I don’t need is not particularly useful (I won’t use it anyway) but the thing is I will be charged for it anyway.
In those countries where MS has now bundled Copilot Pro into Microsoft 365 Personal and Family Plans - not the US yet, so far only a few APAC countries like Australia and Singapore - it's still possible to get a "Classic" version of the subscription at the old price and feature set, but only via the cancellation screen, not otherwise advertised. I wonder, but certainly do not know, if Google has similar plans.