That additional form was for contract tracing. AA sent it to us as a link, on an email, a couple of days before our flight. Completing it online allowed us to avoid having to fill it out in the airport as well. A picture of the email from AA is below so that people have an idea what to look for in their inbox or spam.
We did complete it online. We were still required to complete the paper form at the airport and turn it in at the counter.
