I am trying to use Managed publishing to timed release my app. The app is a new app on the Play Store. The production track is now showing in "Changes ready to publish".
Will my app be live on the Play Store when I confirm Publish changes or I will need to wait for reviews again?
I would like to time the release correctly. I got this question because it took 20 mins for the production track to change from the review state to ready to publish state and what I was warned was that it could take days for the review.



"Changes ready to publish" means that review has been completed, and it will go live as soon as you click "Publish changes". The warning about "within one hour, but occasionally longer" is just because Google has a complex infrastructure with thousands of servers, and it can take time to deploy the changes to everywhere they need to be.
Yes, reviews can often be that fast, but don't count on it happening every time.