If they're in the cloud, you should get them back at some point.
To install the IPSW on the beta:
Sign In - Apple
developer.apple.com
Click on that and sign in with your Apple ID. It’s that simple, and free.
Note: You need to install the MobileDevice.pkg. Download the Xcode beta, then right click it in finder and click show contents, then go to OtherFrameworks/Resources/packages and it’ll be right there.
From <https://forums.macrumors.com/thread...ixes-changes-and-improvements.2391692/page-32>
After obtaining the IPSW, just google how to install an OS and go. I can't remember exact keys, etc., but it's a simple process.