WARNING: Most of the following content is not suitable for DDKs to follow blindly, although you may experiment with it.
Actually, Inseong Hwang (the guy who runs Yeunguseng Dojang) gave a lecture on some of the AlphaGo opening theory, and it makes a lot of sense to me, especially on the idea of walls and extensions: four space extensions are too small because the opponent can attach to make it three (i.e.: make it overconcentrated), five space extensions are too big (especially in front of a wall) because they’re way too easy to invade (at the dan level – and my experience at 4k AGA it’s also still easy).
So professionals are less likely to expend moves on large extensions (part of why 3-4 and its subsequent enclosure is falling out of favor) and instead making corner moves which help the side (corner-side-center being followed more rigorously)
And then there’s the traditional 3-3 invasion itself, which was seen as too good for the person being invaded early because it gives the opponent influence/thickness. But really, as the invader if you just don’t hane at the very end of the joseki (there’s the extra push nowadays, but even AlphaGo waits for that final push, even if it is big) then the person who was invaded suddenly has a cutting point that can be leveraged to make the wall incredibly weak (a 3d at the US Open once remarked “two eyes is the new thickness”), this is especially noticeable if the wall has a five space extension, as now the invasion is not only not too hard, but can endanger the wall that was just made.
But other than that, I’d say most opening theory (in terms of direction and timing) is very similar to what it was before, just that a handful of josekis are becoming more popular, and maybe the diversity of josekis is diminishing.