This right here is the money quote. Google is rolling in cash while paying its employees $X, no matter where they are. Now, they want to say "Oh, because you live in $PLACE, we're going to pay you less."
Did the value to Google of the work these people are doing suddenly go down? No, and not even if they were previously working from San Francisco and now working from South Lake Tahoe, or even Bumfuck Nowhere.
Google knows this. That means this can only be either an attempt to force people back into offices (which are located in more expensive areas), or an admission that they're not willing to pay people for the value of their work -- literally, not paying people what they're worth. Either one of these is a really bad look, IMO, and not really a smart move for Google.