That's interesting and seems like an easy work-around. Just create the first account with a Microsoft account, and then create your real account afterwards as a local account. Then delete the first account you created and you have no more links to the Microsoft account. Seems too easy.
Theres an assumption here the deleting the online account will not cause any other issues. Id like to think it is so, but it hasn't been so easy at all times in the past.
If they’re linking the pro license with the logged in Microsoft account, it may be difficult to remove it or one may need to provide a different Microsoft account with a valid digital Pro license.