Actually, I have tested this myself, and business usage is depleting much faster. A large part of that does appear to be tied to the recent “known” changes. That said, Plus personal accounts are still being affected as well, just not to the same extent.
What is interesting is that, at this point, you are arguably better off with a Go account and its weekly quota, simply because it still allows normal, practical use.
I have also been doing some digging, and it seems quite possible there is a separate issue with Codex and/or the IDE extension. If my testing is correct, a few very simple requests were consuming around 16M input tokens and producing roughly 100k output tokens. That is nowhere near normal, and it would certainly explain why token balances are dropping so quickly.