I really highly doubt that. The way Microsoft uses the “for business” branding is not in an IRS/legal way to distinguish between for-profit vs nonprofit entitie

I really highly doubt that. The way Microsoft uses the “for business” branding is not in an IRS/legal way to distinguish between for-profit vs nonprofit entities. Rather more like “Discord vs Slack” or “a subreddit vs zendesk” type offering. “For Organizations” would really have been a more appropriate branding. Governments around the world, including the US government, used plenty of “For Business” software from Microsoft. However, the “for business” branding tells you where the money came from. So a nonprofit would almost certainly be on a “for business” subscription type. That is to distinguish it from a “for students”, “for home”, or the default “for one person” subscription type.