He floated the pristine servers idea more as an example that the Blizzard developers at least toyed with ideas for vanilla-esque servers, but he did not mean that they were serious about it nor that they were working on it. It's very much like taking an example out of a huge whiteboard of brainstorms to show you they think about all kinds of stuff all the time, but people shouldn't expect anything out of it.
That statement was meant to placate the people angry at them for not releasing vanilla servers, nothing else.