Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
This has been a recent development for Word only at this point, with possible roll out to other apps like PPT and Excel later.
EDIT -- Apparently, as of Feb 24, it now applies to PPT and Excel, or so says the Microsoft help page.
But this still means that copilot is being paid for. This is an opt-out rather than opt-in. So you get stung for the price of something most didn't ask for and most do not want or need.
If you roll back to the now called 'Classic' version you do not get other updates for stuff that may be useful - such as making files inclusive through accessibility updates.