Not only cool, but ScummVM might have been used in creating that article. Scalers are clearly being used in the screenshots of ScummVM supported games. Of course, you can do that with DOSBox, but if they were using DOSBox alone I would expect all the screenshots to show the same amount of smoothing.
It had to have been both. There were shots from games that are not (yet) supported by ScummVM, but it seems that they don't know how to set different render modes in DOSBox. Then there were the other games not supported by either DOSBox or ScummVM.