It might quell some of the more outlandish discussion about Trump as a Manchurian president, but this doesn't resolve some of the other questions re: collusion.
Trump still could have colluded with the Russians previously before performing this major 180.
It's not quite a 180. Trump alerted the Russians before he executed the bombing strikes. While Russia is indeed for the Assad government, Trump is veritably better for the Russians than Hillary was. Electing him was definitely in Russia's interests. Having Wikileaks release information from Putin's intelligence agencies was in Trump's interests. I am pretty sure both sides thought they were benefiting from an indirect mutual collusion. That's pretty clear from the open dialogue and the weakening of the hardline against Ukraine in the GOP foreign policy. So we know that there was indirectly collusion. What we don't know if there was an explicit quid pro quo (and even then so, it's clear both sides benefited from working together via Wikileaks).
In the grand scheme of things, the Syrian action is a limited one, and a highly localized one. They are initiating air strikes from that same bombed air space, because the Russians alerted the Syrian government about the impending American strikes, thus allowing the equipment to be moved, as I understand it. Tillerson has made noises about removing Assad but I'm not sure how 100% the Administration is behind him in following up on that comment.
Ultimately just because Trump is President does not mean that there is 100% agreement between U.S. foreign policy and Russia's foreign policy. Russia backed Trump because they believed Trump would give them a better deal - not that he would 100% act in their interests. As intelligence assets have told the Senate, Trump was boosted both in the GOP primaries and the General, in the assumption that he would cut a better deal for Russia than Rubio or Clinton. A localized strike against Syria's Assad government does not mean that Trump is somehow not a puppet or did not engage in collusion with Russia.
The sanctions haven't been lifted because of the hue and cry around the elections. Trump is unable to lift said sanctions right now. We'll see if he uses Syria as a pretext to lift them, which would definitely be suspicious. Right now, given how closely he's tied to Russia in the public's eyes, he's not really able to change American foreign policy on Russia. Which is a good thing (and I suspect the hawks in the Administration, like Pence and Matthis are anti-Russia, to a considerable degree).
I am still highly skeptical the United States will be a major part of any Syrian peace treaty deal against Assad, because that would require the United States to engage in sustained military and diplomatic work. That's simply not something Trump can afford to do with his isolationist coalition. Remember much of the alt-right is highly favorable to Putin and deeply wary of interventionist strategies, so we'll see if push comes to shove, who they side with.
But the Administration could surprise me. But for now, I assume it's a local strike and a lot of noise against Assad but not really a sustained campaign to remove him from power or to allow a true democratic Syria to emerge. And I assume Trump still wishes to work with Putin more than he wants to antagonize Putin.