Viewsonic did not have a version of the Coretronic 4K LASER Cinema at its stand, just the regular 3500 and 4500 lumen 1080P ones from the current generation that retail for €4200, moving what was a pre-production demonstrator last year to a selling product this year.
And yes as a loyal Coretronic customer it did have the big box 4K XPR projector hanging at its booth."We have no information, we don't know if it even will come or when, it is just a teaser". I can't even remember if it was showing a picture, it was that bland on the wide open and thus well-lit white booth.
Last year's pre-production unit
The version of a Chinese competetitor as shown at the Coretronic stand
Unfortunately no pre-production model based on the U40 4K XPR 4K Laser Cinema,previewed at Coretronic, the world's largest DLP projector ODM/OEMLinkback: http://dci-forum.com/d-cinema-home/11/ise-2017-viewsonic-only-teasing-4k-dlp/1722/