I also recieved this ambiguous message as another members that recieved it more times (2 or 3 times). Also I read in other forums that after some days they recieved a final message like the violate guidelines.
So I can think:
a) Spam Team are out on vacation so we must wait for a final message
b) Spam Team are using for some sites this type of response. Perhaps as tedster told me in my post this sites were reviewed and we must wait because we are in a "penalty box". I also read this thought in another forum.
Also I found this response for sites that are not penalized
@proboscis if you recieve another message from G, please post it here :)