Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
I ended up like the OP and rolling back to an older version of Office software from this link. I disconnected from the internet once I started installing the software to make sure it didn't start auto-updating... You can turn auto update off for all Office software by opening Word, Help, Check for Updates
I also found this article from the Verge saying that this "auto-bundling" of AI Copilot **** is a limited roll out to a few countries - Australia, New Zealand, Malaysia, Singapore, Taiwan, and Thailand. Appears no one was paying for the Copilot Pro add on, so they've just automatically added it to existing subscriptions AND put up the price - straight up "opt-out" evil. My 365 Family plan had automatically been "upgraded" to include Copilot, BUT the cost had also gone up by NZD$50 per year. I had to go into my account and actively switch back to the plan I signed up for, which is now called "family Classic" and is NZD$179/y vs NZ$229 for the version with the AI I don't want... Needless to say I went back to "Family Classic", however that new subscription, without Copilot, doesn't start till next March. So for now, I still need to run the older out of date versions and not do any updates.