While my tumblr account is not adult-oriented, I did import it through Partiko to see what would happen. As far as I could tell, all it does is create a read-only backup that you have no control over. I don't know what the ultimate plan is or if there is one but right now it has nothing to do with steem. Unless I'm missing something. If ultimately you could get a steem account created and your tumblr blog entries posted there (even if it had to happen over time which it likely would), then that would be something.