I wondered… How often MusicBrainz database updates itself when users enter release? For example, I’ve made entry: https://musicbrainz.org/release/cd5384bc-b5f2-4687-b713-4044603d67ea but when I start Picard and check those files, it won’t find that release at all.
Edit: Shame on me. I was using Picard 2.0.3. When I upgraded, it collected data at blazing speed.
The database itself will be updated immediately.
BUT:
There is a reviewing process called “voting”.
As soon you get 3 yes votes, your edits will be applied. If you don’t get any votes at all, you have to wait for 7 days until it get applied too.
You can look how many votes you already got with:
https://musicbrainz.org/release/cd5384bc-b5f2-4687-b713-4044603d67ea/open_edits
So, votes or not, it will get merged into database after 7 days?
Normally: Yes (as long as you don’t get any “No” votes. 
)
The linked document describes the process and the need of more “Yes” then “No” votes in detail.