Form 8863 is used to figure and claim your education credits, which are based on adjusted qualified education expenses paid to an eligible educational institution (postsecondary). For 2017, there are two education credits.
The American opportunity credit, part of which may be refundable.
The lifetime learning credit, which is nonrefundable.
They are asking for it because you must have claimed an education credit. If you did not, answer them and say you did not ask for an education credit.
To check your return for the form, search the term "8863" and jump to the form. If you filed for an education credit, TurboTax would have filed one in for you.
When you amend, you should send any form you are changing but sometimes when the IRS gets the amendment that causes them to check the entire return to see what else they need. It is pretty common.