Issue has be resolved by Azure Support. This seems to be a timely issue, as I wasn't able to reproduce the same behaviour (creating app, deleting it, being unable to reuse the name), however the original three apps names remained blocked from being used. A back-office job has been done and I was able to reuse the apps names again.
Reusing app name from UAE North region is not possible
Mahmoud Abduljawad
96
Reputation points
I gave UAE North region a shot last month, but overall I wasn't satisfied with the performance. I can't confirm whether this is Azure-side issue, or something else, but overall I decided to move the project I was working on to North Europe, which is my region of choice. However, even after 4 days, the three app names I was using in App Service are still unavailable and I can't reuse the names. I confirm I moved apps before from US Central to North Europe without having to wait at all, but with these specific three apps, it doesn't seem to work.