From an interview aired on CNBC's Squawk Box on July 20th, 2015, around 8:13 A.M.

https://archive.org/details/CNBC_20150720_100000_Squawk_Box#start/7980/end/8040

First mentioned by /u/Best-Pony here: https://www.reddit.com/r/mylittlepony/comments/3dxvy6/hasbros_ceo_brian_goldner_said_he_was_a_brony_in/