Mostly because this happened to me, but I have a channel blocked. I have had them blocked for a very long time for various off-platform reasons. I received a randomly gifted sub for said channel today.

If you have a channel blocked you should not be able to randomly receive a gifted sub for said channel. I understand there's an option to prevent receiving gifted subs to channels you don't follow, but in this instance, I didn't think I had to worry about that since the person was blocked already.