Agreed. It’s basically a souped-up version of the dip / wash method - ink-type paints over a white or light undercoat and relying on gravity to run the shade into recesses and leave ‘natural’ highlights on the relief. It’s not new. What’s new is that GW have, as usual, found a way to package, market and monetise an old idea.
It doesn’t do it for me, but a lot of people seem to have picked up on it as a quick way of colouring figures with a passable result at tabletop distance.