Add Feast Ost Themes to top 100 mounts (Previous and future mounts) for example:

1st mount can have the standard feast theme and the reskin mount can have the culling theme. This will make these rewards feel more like theyre from PvP and It's more fitting for a special mount to have the ost of where its from than having the standard mount theme the majority of basic mounts have.

Also consider osts from rival wings and frontlines for those mounts as well.