Might be related to his association with Buds Gun Shop. Hickok 45 is doing Youtube vids of guns then auctioned off at Buds.
He later speculated online that it may have something to do with Google+. “Apparently, Google + is more sensitive about firearms related postings and such,†Hickok45 wrote in a short post on Facebook. “I never use Google+ and did not even realize the videos were being posted over there, I guess. I will keep you posted via Facebook here and the Hickok45andson channel. I have communicated with YouTube via email this morning, and hopefully, we’ll be able to get the channel back up soon. I had just posted a new video.â€
http://www.outdoorhub.com/news/2016/01/06/popular-gun-channel-hickok45-banned-youtube/