The 2016 MBP was so late though because it was a complete redesign, and even with that model, there were rumors that it was originally scheduled for a release around WWDC 2016 and it was only so late because of the issues Apple experienced with the terraced battery design and because they therefore had to backpaddle to the old battery design. I know these were just rumors but still, the 2016 was a complete redesign, this year's is expected to just be a spec bump for the most part.
If we additionally consider that the last MBP released at WWDC and
that all the MBP releases since 2012 (with 2016 as an exception) happened less than 300 days after the previous release, and that Intel's new chips have leaked several times by now and are soo-to-be-released officially, then I deem it very unlikely that we won't have gotten a MBP 2018 announcement after this year's WWDC. It's not completely out of question, I'll give you that – but that's why I only called it "very unlikely" in my original post and not "impossible"