Well, anti-stalking notifications for AirTags have existed on iPhones (and Androids with an app) since the beginning. This only adds built-in support to Androids as well. So, sorry to break it to you, but your system has always been set up to notify any thieves with an iPhone (or a free app installed). Anti-theft is an anti-goal for the AirTag, and, in my opinion, that is the correct choice, because vigilantism is really not a good idea. What would you do with the location of your stolen item? Report it to the police, they won't do anything, and you shouldn't go to that location, the risk isn't worth it.