I suppose that makes sense. Personally, I would write lessons learned rather than learnings in part to get rid of the red squiggle. My dictionaries flag "learnings" as a typo.

"Lesson" also bears this meaning of something learned, though that would make "learnings" more precise, and therefore distinct.

My experience seems to be that people who use "learnings" are referring to the lessons learned by others, usually subordinates and is used instead of "lesson" because of -- being sensitive to how harsh it sounds to say "group X learned several lessons".