I think you misunderstand OneDrive. You have only uninstalled the local OneDrive on your computer. You still have the cloud-based OneDrive that is associated with your Microsoft Account,
When you have OneDrive installed on your computer all the files in the "C:\Users\<yourusername>\OneDrive" folder are backed up to your OneDrive cloud storage. If you remove OneDrive on your computer the OneDrive cloud storage is still there. You can either use it or not. It is your choice.
The following assumes you have followed the steps given in Post #6.
You will always see
OneDrive - Personal as a Save As option when you are logged into your Microsoft Account in Word.
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If you are logged out of your Microsoft Account in Word you will stop seeing
OneDrive - Personal as a Save As option.
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Of course if you have Microsoft 365 you probably want to stay logged into your Microsoft Account.
I have Office 2021 Pro Plus so I only have to log into my Microsoft Account if I want to. Even though I don't have to log into my Microsoft Account I do because my documents are auto-saved into the OneDrive cloud storage. That way I will always have a backup copy that isn't too old.
Note I also have OneDrive uninstalled on my computer. Like I said this is not the same as the OneDrive cloud storage.