Interesting. I would have blamed it on a machining defect. I'll have to look at a few chainrings I have around here carefully.

I'm trying to figure how such a sloped valley would impact wear. Initially I would not like the idea, especially if it was on a cassette. But, it may not do much on a chainring, depending on tolerances. It appears to be more of a slope to the pulling side of the tooth which ordinarily would be bad. However, in effect, the sloped valley would also tend to pull the chain tighter against the teeth which might be good.

It would depend a bit on the actual two radiuses.