The information itself isn't federally or state prohibited, though, right? If they didn't want to "deal with" it, then they shouldn't have a specific policy about it at all. Unless the government (or the courts) were pressuring Google on this issue, then it is simpler (and arguably fairer) to not try to be the arbiter of what is and is not allowable speech.

I can't speak for the people that create these channels or want to make these expressions, but I have to assume that at least some of them think that they are making people safer by teaching them how to legally arm themselves. That seems to be a view that Google disagrees with, so they have implemented an editorial policy on YouTube which prevents people from expressing that view in a meaningful way.

Perhaps you think that Google would only be banning people for their political views if the company openly said to them: "We are banning your channel because of a political view you have, even if you never express that view in any of your videos." That seems like an unreasonably high bar to require though. If Google said "You can support any party you want, but we won't allow Democrat political candidates to put their campaign ads on their channel." then that would, at least to me, be a ban on political views.