It could be tricky with permissions on different users: for instance you authorize google.com/maps to track your location while logged as user A.
You logout and switch to user B to look at another Google service, but google.com is still allowed to get your location, and will stick it to user B, which is something you might not have wanted. This didn't happen with the previous domains, so could be a surprise.
You logout and switch to user B to look at another Google service, but google.com is still allowed to get your location, and will stick it to user B, which is something you might not have wanted. This didn't happen with the previous domains, so could be a surprise.