Update: I went to the Audi dealer so they could inspect the coolant tank. After a brief look, they came and told me that they would need to attach the strap to the tank. They said they could do it today, and they would give me a loaner. I didn't want to deal with it all today, so I scheduled an appointment in a couple weeks to get it done. They are going to give me a loaner on that day, which will be convenient.
The thing that drives me nuts is that I originally asked to have the recall done. After being told by the dealer it didn't need to be done, Audi North America straightened things out and connected me with the dealer. They then told me again that it didn't need to be done. We decided on having it brought in for a safety inspection at the very least. And now, here we are scheduled for the strap installation. Seems like a lot of my time wasted just trying to comply with the recall letter that Audi sent me.
At least, the end result will be that I know I have a replaced tank with the strap installed. So I should be in good shape at some point here. Just a little bit aggravating that this wasn't a simple process.