If an app is submitted and released with a version requirment of iOS 11+, can a subsequent submittal and release of the app downgrade the required iOS version to iOS 10+?
It's quite simple to set and submit the new version requirement (via iOS Deployment Target in Xcode) but I am hoping that someone can confirm that that will work seamlessly.
I have only ever *downgraded* version requirements before!
>submitted and released with a version requirement
If by 'required/requirement' you mean base (max) iOS version (vs. deployment/min OS), you can't take support away from current users, so, no, in that example you can't 'downgrade'.
As for lowering (expanding support) the deployment OS, sure, go for it, just be sure it doesn't break anything.