The upgrade process is to either:
1- remove third party repository packages before the upgrade, and re-add the packages after the upgrade, or
2- add the third party repositories to the upgrade process (it's an option during the upgrade), so those packages get upgraded as well.
In order for you to use the second option, the new repository for F8 must be ready. Some (like livna, ATrpms) have announced the new repository is ready, while others have not. It all the packages you need are in those two repositories, you are good top go.