RC14 Beta 6. The Guardian Angel perk adds an additional tier 7 creature earlier, at level 20 (definitely at level 19).
Witch huts offer a skill, although both of the suggested skills are already expert-level (previously, it just said that there was nothing to offer). And for the second hero, without these skills, after confirmation, the skill is not added. And after that, it's the same in all witch huts encountered on the map.