Changing default app location.

I have Game Pass and want to install a few games, however, when I choose to change the default app location in Windows it mentions it will have to remove existing apps on the other drive.

C: Is my OS Drive and has all my game modifications on it, D: However is for Steam and other games.

What exactly will I lose by changing the default location, as it mentions that?

Winver: Version 20H2 (OS Build 19042.804)

Because my issue isn't about Steam, it's about Game Pass.

I simply want to change the default app location to install Game Pass games, I just need to know what exactly will be removed if I change it.