I upgraded to iOS 14 on my iPhone SE. Yes, I can change the default web browser from Safari to Edge, and the default mail app from Mail to Outlook. But, if I restart the phone the defaults revert back to Safari and Mail.
innitrichie
<p>It's undoubtedly a bug. This wasn't tested during the betas because apps were not permitted to be updated to support setting the defaults. So now the bug is uncovered, it will be quickly fixed in a point release.</p>