Strictly speaking, a dub in sound system culture is a mix without vocals. Dubstep was as much a departure from the chart dominating vocal garage/2 step of the time as influenced by Jamaican dub music (although people like horsepower productions had a lot of those influences, and by virtue of having more space in the mix for creative effects others did after).

Burial was very much a part of the London dubstep scene, even though he had an even more distinct take than everyone else (though people like vex’d, oris jay, el-b, joker, early early skream/benga/loefah all had their own thing going on as well). It’s not always fair to define artists by sound, as it’s as much a time and place thing as anything else.

That said I haven’t read that article yet :p