When submitting to Google Play, they throw the following warning (and near-future error):
"Warning
Your app currently targets API level 29 and must target at least API level 30 to ensure it is built on the latest APIs optimized for security and performance.
From August 2021, new apps must target at least Android 11 (API level 30).
From November 2021, app updates must target Android 11 (API level 30)."