Apple didn’t mention the new feature on stage, but it is included on the Preview website for the update.
Set default email and browser apps. With iOS 14, you can set a third‑party app as the default email or browser app systemwide.
With this option, iPhone and iPad users who prefer third-party email apps like Spark or Edison or third-party browsers like Chrome or Opera will be able to use those by default when tapping on links that compose mail messages or open browser windows.
Apple has been criticized for forcing iOS users to use its built-in Safari and Mail apps, with no option to change those defaults, so this should be a welcome change for those who prefer third-party apps to Apple’s own apps.
Apple also plans to allow third-party music services to be used on the HomePod for the first time.