I believe the App Store has switched to automated reviews, at least for updates. I've had my app updates approved in <1h on a regular basis starting this summer.
From what I was able to see from the outside, App Store has had semi-automated reviews for updates in basically forever (+ some random spot checks), presumably based on some introspection that only triggers a human review if a new system API was used.
Yes. And the Play Store now takes several days for approval for updates of existing apps.