There's a standard Mock Location feature in Android usable for it. We're making a better per-app Location Scopes feature as a replacement. Mock Location is global which has bad usability.

That's true. Do those caveats from that older comment still apply? Will apps be able to tell that location is being spoofed when using location scopes?

Hopefully not.. Otherwise it defeats the whole purpose. Right now there is no way for apps to find out media and contact scopes, so it might be something similar.