We've had exactly the same drama with the 2013 rMBP reviews, see the corresponding thread here: https://forums.macrumors.com/threads/1667236/
Same story: Multiple tweets about it, Hellhammer coming in at some point to comment on the delay and confirm that it will come, etc. In the end it never arrived.
Now the 2013 MBPs didn't have any groundbreaking new features. Marginal CPU and GPU upgrades, PCIe SSDs that were benchmarked on the MBAs already, and TB2 which was looked at in the Mac Pro review.
The 5k iMac has more really new things in comparison, with the screen of course, the custom display port thingy, the high end GPU which is the first AMD Tonga GPU (afaik), so I'm still hopeful that it will arrive at some point. But there were also major changes at Anandtech recently, and new products and events keep happening that need to be written about, so I wouldn't rule out the possibility that it will never appear...
Thanks for the information. It seems, sadly, that history might repeat itself.
I guess I was a fool to believe Ryan Smith's word. It seems these people can't be trusted.
Lesson learned.