When I said Putin did it and the US did not, I was only referring to the demo of the Russian cruise missiles, not the state of play in Syria. Your description of the state of play sounds good to me. I'm also a bit concerned over how Turkey and the Saudis will react, and maybe even Israel.
If the Saudis start providing more sophisticated weapons they might find themselves being dragged into the war directly, not by proxy. If those weapons include smart missiles which were sold to them, the specs will be well known. It looks like the Russians want to test and demonstrate their latest technology, which is not available on the open market, and which will include countermeasures for existing weapons.