What does the publish command apply to?

Hi, I have this app on the play store. I just built the new version and released it to the play store and is currently under review. I noticed a small bug after I submitting it, so I was wondering:

What happens if I fix it and publish? Will all the aabs, old and new, get the update? Or maybe only the last build gets the update? Will all the users that already installed the old version get the update before the Google review process is completed or will it apply only to the one currently under review?

update will affect all builds that use the same version of expo sdk. When app starts it checks with expo server if there are new updates and downloads it, but that new code will not be executed until app is restarted, so in your case it should switch to the new case on the second app launch. Not sure how it will affect play store review, but for app store review is very likely to be rejected if you do sth like this

Look into release channels too.