From a friend: "They seem to have rescinded a lot of it, albeit with a shitty nonapology blaming users: <link to this post>. Some of the tags in question could never [have] brought up porn, like 'depression'. I call at least partial bullshit."
Not sure what the 'depression' tag has to do with any of this - it is not filtered, it returns results, and it has a PSA at the top of the page as with other specific keywords due to the nature of the search query.
Depression probably returns self-harm images, which Apple would obviously block.