This account cannot be added. The license provided by your work or school does not enable access to.

I have the same issue.  This is a cash grab and I'm pretty sure we can look into a class action.  I, personally, maintain a business basic and a personal account.  I don't actually use the business basic account for business, I just liked the ability to utilize certain features of 365 that weren't available via other methods.

So they want me to.... buy outlook twice?  Something doesn't seem right about that.