How many of you are there left? 2? 3?
Mac Pro market share estimates vary, but Apple sells somewhere around 500,000-750,000 Mac Pro each year. I’m sure volume has decreased as the 2013 platform has gotten older and older, even with the price decreases and configuration adjustments last year.
Those that can hold out until next year are definitely not buying until the new platform ships. Some can’t wait, and continue to buy as needed, or buy iMac Pro (or leave the Mac platform altogether, for the short or long term).
But certainly the iMac Pro has permanently cannibalized a slice of formerly Mac Pro demand. And similarly, iMP has also taken a bite out of high end 5k iMac sales—a fair chunk of which came from customers that at one time bought Mac Pro, before high end iMacs became powerful enough to meet their needs.
Overall, it seems likely that Mac Pro + iMac Pro will have larger sales than did the Mac Pro alone, and I wouldn’t be surprised if iMac Pro outsells the 2019 Mac Pro ongoingly. I think Apple would be very happy with iMac Pro at 3% and Mac Pro at 2%. Both platforms should have room for growth as Apple proves their commitment to pro users with updates at least every other year.