I don't consider a handful of outspoken developers who have their own blogs to be "en masse". Every developer that I know still uses a MacBook or MacBook Pro. The new MacBook Pro is a great product. If you don't like it, don't buy it.
I know a handful of people who normally upgrade every refresh and are flat out refusing this time. A couple (that aren't locked in by being iOS devs) have picked up other laptops instead.
I disagree with your assessment that it's a "great product." I bought a spec'ed out one myself that I eventually returned.
Not claiming either one of us are the majority but I wanted to add my side and not state it as ultimate fact and certainly not present it argumentum ad populum.
Apple fanboy after reading a new blog post on how developers with a huge followership give up their MBP, which are ranking in the top of HN every day since the announcement in Oct 2016: "These developers are only a minority. There's definitely no trend here whatsoever. 100%. Trust me. It's based on my opinion."
"If you don't like Trump, leave the country". "If you don't like the video, don't comment, just ignore it"...And then what? Let's all just shut down threads that crticise anything at all, because, of course, if I don't like it, I can just move on.
This is not synonymous with upgrading their MB/MBP.
My biggest dilemma is not whether or not to upgrade my aging 2012 MacBook Pro Retina with a 2016 model. It's whether or not I should buy the 2015 version while it's still available in some stores.