There is absolutely no anticheat that bans hackers instantly. Of course there will still be hackers, in fact more often than not these hackers we run into are only on their first or second game of the day. If they aren't banned by the anticheat's detection and they're blatantly hacking, they'll be picked up by a mod.
However, this isn't to say the anticheat is perfect. In fact, it is currently being developed to detect a wider range of hacks and such. Unfortunately closet cheating has yet to be formally addressed though on the bright side I have sent up many a proposal and explanation to the administration of the premise of closet cheating and how to effectively go upon stopping common methods of the sort.