Users with the latest devices or those completely caught up in Android updates expect to realize the full potential of all the privacy and security protections Android has to offer. Expanding our target-level API requirements will prevent users from installing older apps that may not have these protections. Starting on November 1, 2022, existing apps that don’t target an API level within two years of the latest major Android release version will not be available for discovery or installation for newly registered users with devices running Android OS versions higher than apps’ target API level.
Don't worry if you rely on an old app. You'll still be able to use it and get updates. Your phone will only get into this situation if you clean format it or if you install it on your new device. To be more specific, apps that target Android 10 and earlier will be included in the blocking list.