He probably has seen a script, or at least head what the intended story will be (which likely contradicts the EU). M.rudolf apparently has insider information on the Disney company (so then by extent, Lucasfilm).
I was under the impression the EU wasn't canon from the start. I mean I've heard elements of it made it into the prequels and such (like planets or characters), but the stories themselves might not actually occur. I've never read any of the stories myself but i've looked up some of them (though I guess the Knights of the Old Republic and Force Unleashed video games count as EU and i've played those). The fanbase apparently are pretty divided about whether to accept them as canon or not. Many believe "if it didn't happen in the movies, it didn't happen at all". If this new series does contradict the EU in a huge way, then yeah the EU would be knocked off the canon.
Though it does seem that some of the EU material might actually inspire some of the canon material. I wonder to what extent though. From what M.rudolf has indicated, current story plans might include a clone (or clones) of the emperor. The emperor has apparently had a number of clones in the EU. If that happens then I hope they get someone awesome to play him, Ian McDiarmid always managed to steal the show and I couldn't take my eyes off of him whenever he was onscreen. If he's going to get a clone though i'd probably guess they'll end up getting a younger actor to play him. I'd imagine one of the points of a clone would be not being tethered to an aging body. I don't know what younger actor they could get to pull the role of youthful Palpatine off, but it would at least be interesting to see them try (if Ian himself didn't return).
Are any characters introduced in the EU going to appear at all such as Mara Jade, Anakin Solo, Jaina and Jacen, etc? Or are they all now completely non-canon?