Simple: have them sign an amendment to the lease stating the new name of the property owner. 

And the 1st Amendment .

I would then make a note of this and amend your lease for next time so it is spelled out in the lease. 

Chalk everything up to experience, amend your lease, go back and do it again next year.

When they give notice you can notify them of the shortfall due for that final month as part of their move out letter.You can cover agreement wording changes with amendments or new agreements.  

In cities where ADU's have a history there has been no over-saturation of them, which is why there was no heartburn by legislators to amend the bill with a sunset provision to the issue.Thirty years ago in my city developers were allowed to knock down a SFR and replace it with a three-story 8 unit behemoth with vastly insufficient parking.

This would be our first condo purchase.However, I just received the copy of the bylaws which they amended 2/16/16 and it states that any tenants must be approved by the association and the association has 30 days to approve.  

So, you should be able to amend that. 

With that in mind, here is how I have it written.Resident shall be liable for the payment of real estate taxes with respect to the residence, in accordance with the terms and conditions of Section 200/15-175 of Chapter 35 Illinois Compiled Statutes, as amended (35 ILCS 200/15-175,(1994).

Nonetheless, if you paid SE tax on your rental income in 2016 and earlier years, you might be able to amend your tax returns and get some money back.Let me know if any questions.