It sounds to me you are saying there's WHL and WHL-U? There's only WHL-U according to that site. WHL-U is a replacement for KBL-R with the extremely limited information we have. KBL-R launched around August this year, so BTS 2018 for WHL-U makes sense.
Again according to that information, Icelake Y/U is coming 6 months later. Perhaps Icelake is only a two core part, and that's why we need Whiskey Lake. Otherwise, Whiskey Lake is a very short lived part that'll be ditched by most manufacturers. Or, as I have said there's something in Whiskey Lake that doesn't exist in Icelake.
Parts like Whiskey Lake and the rumors of 8 core Coffeelake must exist because there's no way Intel could have any Icelake parts in 2018, yet they need new product to sell.