I bought my current trash Pro 6 years ago and I find LR to be irritatingly slow on my Hasselblad files (LR issue obviously), so upgrading to a faster machine is appealing.
That seems odd. I'm also using a 2013 Mac Pro as my primary platform for photography (six-core 3.5GHz Intel E5, 64 GB memory, upgraded third-party 2 TB SSD), and consider the performance still to be acceptable on Fuji X-T[12] and Nikon D800E files. Rendering is quick, slider performance is responsive, and even computationally-intensive functions such as
Dehaze (only slightly more latency than the other sliders) and
Enhance Details (typically about 15 seconds to render) perform quite well. Some third-party apps that demand a lot of graphics accelerator compute cycles—e.g., Topaz
Gigapixel—are quite sluggish, but I don't use them very often so they wouldn't justify upgrading to a machine with more powerful GPUs.
Seems to me the 2019 Mac Pro is a product designed for commercial video production and parallelized or graphics-intensive scientific applications—which, no doubt, is how Apple defines its "pro" customer base. I'm sure they'll sell a lot of them since many of these potential purchasers (1) have UNIX dependencies or (2) have applications that don't run on Linux or (3) can't abide MS-Windows.
But to return to your original comment, my feeling is that either there is something strange about the way Adobe handles Hasselblad files, or something unusual about your software environment.