What's unfortunate from a Mac product line standpoint is Threadripper's modest RAM capacity. Sure, 256 GB is a lot by any normal standard - but it's modest by the standards of Mac Pro-level workstations. Most people don't need >256 Gb of RAM, but many Mac Pro customers do...
Right now, an AMD workstation requires one of two compromises...
Threadripper, which is very fast, and is even fast in poorly threaded applications, because each core boosts to a very high speed - but has a relatively modest maximum RAM capacity...
OR EPYC, which will take absurd amounts of RAM (isn't it something like a 4 terabytes per socket, and dual socket designs are possible) - but it's slow unless your application is well-threaded, because it has a low clock speed (a lot of cores, but no fast ones).
Sure, you could put Threadripper in an iMac Pro, which has a 256 GB RAM capacity - but how do you cool it (maybe a new iMac Pro case based on the XDR display design could) - and, regardless of whether the Mac Pro used EPYC or Xeon-W, the iMac Pro would usually be faster. If the Mac Pro were EPYC, the iMac Pro would clock much higher, and only applications that could use more than 32 cores would be faster on the Mac Pro (assuming a 32 core Threadripper and 64 core EPYC). If the Mac Pro stays with Xeon-W, only the very fastest 28-core is even in the running.