According to #578 it appears that v8.0 modified the OverlayView component to use unstable_renderSubtreeIntoContainer in order to retain context. This is no longer useful, as this method is not compatible with React 16 context and will likely never be (see here). it also looks like we are nearing the complete removal from the API completely (see here). It looks like this effort already took place, but for an unknown reason skipped OverlayView (#640).
According to #578 it appears that v8.0 modified the OverlayView component to use unstable_renderSubtreeIntoContainer in order to retain context. This is no longer useful, as this method is not compatible with React 16 context and will likely never be (see here). it also looks like we are nearing the complete removal from the API completely (see here). It looks like this effort already took place, but for an unknown reason skipped OverlayView (#640).