Yes, even without FMODStudioCache.asset, everyone working on the Unity project should still be able to hear the updated sounds, as long as the FMOD banks themselves are built and available. The cache file is only used locally by the Unity Editor and is not required for audio playback.
Yes, it is still possible to remove FMODStudioCache.asset from source control even if it was committed previously by other team members. Once the file is no longer tracked, it can remain local-only and be regenerated per user.
There is a similar discussion covering this behaviour in Unity Version Control / Plastic here: FMOD.log keeps checking in ignored files in Unity PlasticSCM Source Control - #3 by Connor_FMOD