It doesn't surprise me at all, though I imagine it's going to make some people really unhappy in the fan community.
That said, such an official statement might have just been the first shot in a war that is going to wreck the entire thing depending on how it goes. Simply put, Star Wars has had some rather interesting contractual issues over the years and right now I'd imagine a lot of writers publishers are currently going over the fine print in their contracts and/or contacting their lawyers and notaries (notaries being important because they can be used to argue what the understanding of a complicated agreement was, which can trump what was actually written, this is why for a lot of contracts both sides will have at least one notary present to counter-sign... it can get complicated, I learned some stuff about it in school, but Contract Law wasn't a specialty).
So far George Lucas has pretty much "sold" the rights to Star Wars and the canon twice. The first time was in the creation of a bunch of "Young Adults" books with titles like "Prophets Of The Dark Side", and "The Glove Of Darth Vader" which weren't exactly wonderful. In this version which was the official future by agreement, The Grand Moffs decided to produce a false heir to step in on Papaltine's throne, who would actually be their puppet. This was a guy called Triclops (if I remember) who didn't have force powers, but faked them with cybernetics to "prove" he was the heir, using things like Tractor Beams to perform telekinesis, and energy projectors in his hands to throw "force lightning". The second time was when he sold the rights to "Dark Horse Comics" which lead to them doing a lot of work, George actually got into a legal battle with them over this when he wanted control of the property back, part of the settlement was if I remember that "Shadows Of The Empire" would be officially considered part of the canon along with some other things. In these cases George pretty much sold Star Wars because he underestimate how much money could still be made off of the property and how long it would go on, and pulled the "original creator" card to get sympathy when in court.
I'm unsure of the status of the current EU which picked up with Timothy Zahn's writings about Thrawn, and what was agreed on then. Indeed it was around this time that the term "expanded universe" started slipping into the popular vernacular. It went on so long to become unwieldy, with too many writers, and too many contradictory ideas addressing the same basic material (like Mandolorians and their nature). With the sheer number of people involved though a lot if it is going to come back to what agreements the publishers had.
See, "canon" can be a valuable thing. Half the point of a lot of published novels, and what allegedly makes them better than someone's "fan fiction" is that they were done under the license and had to be picked up/approved by the publisher holding it. Your published work being "true" and "the real continuation" is a big part of the selling point and something your professional career and the value of the parts of an ongoing IP you developed are going to be under.
I remember years ago, George Lucas allegedly said there would never be Star Wars sequels because he wasn't going to step into this minefield. He's sold the rights yet again, and honestly the current overall holder is big enough where I don't think he'll ever get full control back again (he's not dealing with a comics company this time), but even "The House Of Mouse" could be in for some serious headaches if individual writers and publishers show up contract-in-hand and a valid argument. The sheer number of suits, settlements, and/or pay outs could be staggering.
I'm also reminded of Sony running "Star Wars Galaxies" back in the day and how they apparently needed to get permission when they added things into the game, not to mention it's tie ins with things like the "Death Troopers" series (Zombie Storm Troopers). It seemed like very careful track of the rights and what was being used for what was still going on, and now all those same bean counters are going to be equally defensive here. Except in this case there will probably have to be guarantees of "this remaining canon" and "you'll need to mention these things in your material to validate my work or I'll sue for breach of contract" or whatever else.
I'm probably overthinking things, but it will be interesting to see how things turn out. To be honest it seems like the rather broad strokes they are taking here could backfire on a lot of levels. The guys doing the new movies of course want to pursue their own vision and not feel tied down by anyone else's work. Of course the guys who themselves were in the same position when they were writing and got the rights, think the same thing. I was never heavily invested in the EU to begin with (and feel some of it was rather dumb, and missed the point) so I'm fine with them axing it, but then again I neither had a career based around producing Star Wars material, nor did I invest heavily in EU material to the point where it becoming devalued or irrelevant bothers me.
