I'm not sure this really advances what we know; the "100% intermittent renewables + storage" strategy does get asymptotically more expensive as you move towards 100%. So the referenced article points out that a blend of dispatchable gas+capture and "advanced" nuclear can produce a cheaper overall result.

But! Nuclear takes ages to build, advanced nuclear even longer, and gas+capture is deployed almost nowhere because there's no negative carbon pricing for it.

So perhaps they are viable in the long term. For 2020? Countries need to be accelerating their wind and solar rollouts and using them to push carbon-emitting sources down the dispatch order as far as possible.

The UK is surprisingly far ahead on this, having eliminated coal for most of the year and running a gas/nuclear/wind mix currently at 30% wind.