I agree with you.
A sub 2 hour marathon may come sooner than people think. Chicago is a tough course (so is Boston). Yet each has seen such incredible times that you wonder what would happen if a good runner trained for the record and the day was good.
I think Berlin's value is all in the mind
One thing that Kipsang, and Haile before him, proved is that to break the Marathon record, it is more important to do consistent splits throughout, reserving energy for that last sprint, that to try for a fast first half or a negative split.
"The opposite of a correct statement is a false statement. But the opposite of a profound truth may well be another profound truth." (Niels Bohr)