I think it's resolved for now. The end of Oathbringer seemed pretty conclusive to me. One of the advantages of the love triangle is that it allows Shallan to see Adolin's faults, which is vital in moving their relationship onto the next level. Whenever she's with Adolin, she tends to focus on positive things. It's only when she compares him to Kaladin that she sees where he's lacking. She realises she loves him anyway and chooses him. Similarly, Adolin learns that Shallan has split personalities and still loves her anyway. Then they get married, which makes any relationship between Shallan and Kaladin very difficult indeed and I can see both of them having an aversion to adultery. In my mind, the wedding was Sanderson's way of concluding the issue before the one-year gap. Of course, I'm sure the marriage won't be smooth-sailing, especially because they'll have to deal with Shallan's issues and a world at war, but that doesn't mean they won't be able to get through it. They clearly love each other.
Personally, I hated the love triangle. Love triangles are bad at the best of times but very difficult when it concerns three of your favourite characters. I would definitely not want it to return. I was for Shadolin all along, so was delighted at the ending to OB (and bought it). I was also really happy that Kaladin realised he never actually loved her (which I do believe, by the way). I also think that, narratively, there's no reason to keep it going. Romance is a side story and, as far as I'm concerned, the love triangle story has been told and resolved. There's a much more important story going on and going back to the love triangle just detracts from that.
However, this only applies to the first five books. Characters/circumstances could change a lot in the gap between books, which makes Shalladin plausible again. I think that if Shallan and Kaladin do get together, it will be in the second set of books, although I don't know if these characters are going to be around/relevant enough in the later books for this romance to be a plotline. For now, though, I think the issue is resolved. I don't see any of the characters changing enough in the next two books for the triangle to have a different outcome. Besides, I think Shallan and Adolin are really good for each other and it would be a shame to ruin that. Kaladin has Bridge 4 for support.