Second article and I still don't understand why they can't at least do a spec bump every year. If not possible due to suppliers a price drop should at least grab some market share. With the resources Apple has, anything else is simple negligence.
I guess they were really really close to the edge with that design, and Marco said he's heard those GPUs are failing from heat issues fairly often.
https://techcrunch.com/2017/04/06/transcript-phil-schiller-c...
This is combined with the fact that the Mac Pro sells in the "low single digit" percentage range of Mac sales means that it's hard to justify an outsized expense. When factoring in R&D costs, my guess is the Mac Pro has much lower margins than other Macs.
Killing off the development platform for your successful products is incredibly shortsighted.