While the witch huts themself do render in, the witches don't seem to do so in my Friends realm om hard mode. Although the cat does spawn in, the witch doesn't. And doesn't respawn later as an attempt for a witch spawner. The witch hut is on level 61, it has been darkened on the inside to increase chances, but with no succes after waiting 2 hours in a range of 25 to 30 blocks distance from a straight line north. It also doesn't work from above. There also aren't many spawns outside of the witch hut, but those have been only for the last 20 minutes. There are no other players online while waiting for the two hours.