Your teacher told you it was about censorship. She might also have mentioned something about soviets, but only because for a time every single book ever written was about how the soviets were bad. It's not actually about censorship, not in the literal sense that's played out in the book where offensive materials are destroyed. It is, somewhat, about the dumbing-down of media, but that, like the censorship, is not a cause in the book but a consequence. If you look at what the characters are doing, it appears to be nothing more than a censorship ridden consumerist society. You have to look deeper at why their society is that way. The book is actually about a much more subversive form of self-censorship, political correctness. Bradbury describes a society that values political correctness above all else. They value it so much that their television programs show no conflict and in fact have no substance at all, in case it would offend someone. They value it so much that they destroy all evidence of anything offensive in the past. They force everyone to conform, so that no one is different. The book is really about political correctness run amok, and the censorship is just a consequence of that. The root of the problem in their society is this refusal to admit that anyone is different. It has gotten so bad, by the time the book starts, that these people actively abhor anyone who deviates. It is also, yes, about the evil of television. From Bradbury's perspective, television was the driving force behind political correctness in the first place. Why didn't your teacher tell you this? Ironically, because being against political correctness is not politically correct.
A side note, I'm having a hard time imagining a world view where the author of a work isn't the authority on what that work is about. Authority has the word Author right there in it.