We use -O2 in production at Instagram. The primary motivation is memory savings from stripping docstrings (this we absolutely must have), but it’s currently impossible to get that without also stripping asserts.
Personally I think it would be nice if one could opt in to docstring stripping and/or assert stripping orthogonally from each other, rather than in an arbitrary layering. (In what way is stripping docstrings “more optimized” than stripping asserts?) This wouldn’t require deprecating -O or -O2, they could continue to have their current meaning, it would just mean adding new options. It would require changing the pyc file tagging strategy a bit, but that’s not a big deal.
I don’t actually know how much efficiency gain we get from assert stripping; I suspect not much. I know at some point in the distant past there was an outage because an engineer used an assert wrongly, and assert stripping in production made a problem worse than it would have otherwise been. Because of that, there’s been some cultural holdover ever since (even reified in the form of lint rules) to avoid asserts entirely 
So that’s a point of evidence that developers not understanding assert stripping can cause problems.
I still don’t think assert stripping as an option should ever go away, though. It is a useful tool to be able to write (possibly costly) invariant checks for development and testing, and skip checking them in production where performance matters.