Jeff is worthy of his meme god status, but I do wonder how OW will evolve with new direction. I am hopeful for OW2, so maybe Aaron will simply be steering the team in a direction that are well on course for already. And maybe that's why Jeff has left now, who knows.
Overall though, OW has definitely been lacking in certain key areas (continuous fresh content updates; monetization; cross-plat play, etc) and I have to imagine some of that stagnation fell on Jeff's shoulders. We will see how things pan out ...