Asano Inio did an interview with Comic Natalie on Madoka Magica in the presser lead-up to the third movie. The process of how they arrived at that particular person for that particular interview subject is quite fun, and outlined in the article. The main body covers how Asano came to try the series and which parts stood out the most to Asano personally. Nothing too revolutionary in the article itself, but it’s just generally fun to get great creators’ perspectives on great things, involvement be darned.
The interview is conducted in the leadup to the third film, so Asano hasn’t seen it as of this interview, though it does come up. As an amusing aside, while googling to see if it had been done, this article erroneously citing it as a source for Asano’s approval of the movie popped up.
Original Article: http://natalie.mu/comic/pp/c_madoka_magica