A single query to the Google DNS server does return the CNAME - but it also gives the results to the CNAME. Which means, from the single packet reply, you get back the A or AAAA that you asked for. Are we really concerned over a few extra bytes?
The fact that Google exposes the CNAME at all is just an implementation detail; one that has no practical impact to us. It might have simplified their serving platform - static DNS entries vs GSLB. But they take the effort to collapse the answer, and give an actionable response with the single packet. No extra round trips. Much nicer than some other implementations I've seen for serving both static and GSLB DNS assets.
