I wonder if this puts to rest any ideas of a refreshed Intel Mac Pro, or if it's now completely done and just waiting for the AS Mac Pro.
There was 0% chance that Apple were ever going to refresh the 2019 MP.
A) Apple have historically updated the Intel Mac Pro very sporadically. During 2009-2012 the MP was essentially unchanged. The 2013 MP wasn't updated for 6 years. The iMac Pro never got an update during its 2017-2021 lifespan.
B) Apple have historically been quick to discontinue technologies they see as obsolete. The infamous 'courage'. They aren't sentimental when it comes to moving on e.g. dropping 32 bit application support.
C) They want to get the architecture transition done ASAP, so they can drop Intel code (and AMD drivers) from macOS and standardise company-wide on ARM. Bringing out new Intel machines would drag this out; if they released a new MP model in 2022, they couldn't drop Intel until, say, 2028.
D) Apple Silicon is fast enough that for 2019 Mac Pro money, they can make a monster SoC package with multiple Max dies that is fast enough for practically anyone.
E) For anyone whom an AS MP can't serve e.g. people who need Nvidia GPUs for VFX work, Apple is quite happy for them to use a PC workstation. They're all-in on the AS SoC architecture, and aren't going to provide a completely different system architecture and code path for 0.01% of its user base to use PCIe GPUs.