On Friday, I received an email thanking me for contacting customer care and letting me know that that 10k miles would be deposited in my account. The miles appeared on Sunday afternoon.

The thing is I'm not sure why I got the miles. I did fill out one of the "new" surveys after a recent flight, but other than a few minor complaints, didn't have anything bad to say.
I also sent United an email a while back pointing out the deficiencies in their new boarding passes and including an attached file with images of a pre and post merger boarding pass to highlight the differences, but I had received a very generic response to that email that did not indicate any miles were coming my way.

The wording of the email was: "Thank you again for taking time to let us know about your recent experience with United Airlines.

10000 bonus miles have been added to the MileagePlus account"

Anyone else get miles for filling out the survey?
I'm very happy to get the miles, but just wondering what prompted the response from UA.