Of course 9.5 is the current release so the answer is Yes, since 9.5
It seems like there is some confusion about what we're talking about. I am talking about incremental updates to a sort of "fake" materialized view (implemented as a table). This is totally different than what we currently have implemented for actual materialized views (REFRESH CONCURRENTLY). Concurrent refresh just minimizes the time the view is locked by building a second table in the background and merging the changes between them.