The head scratcher with the next Mac Pro is : what will the RAM situation be?
I'm also wondering what the GPU situation will be. It will be safe to assume it will be more powerful than the Mac Studio but how will it compare with, say, an nVidia Quadro RTX A6000? Since this is what comparable workstations can run, but also, this will define the ceiling for what an Arm-based Mac is capable of doing in 3D applications.
It's delays are only making software developers less confident in the platform (and remember, the Mac Pro has been a challenging proposition for quite a few years now, having lost ground with the trash can and not supporting nVidia options in the subsequent cheese grater).
Its possible this machine will be exactly what everyone needs from a high end workstation but its easy to be skeptical. If ram or gpus are not upgradable, it may be a dead end.
I would really like to know how many people actually need the power of the Mac Pro. If they do, is it worth the cost. I know that some people say that time is money and the Mac Pro will eventually pay for itself with time saved but since Apple has not given any significant update to the current Mac Pro, it tells me that it is not that important in the lineup. I can imagine that a lot of users with more money than me just buy it for the bragging rights.
I would argue the market for a high end workstation is probably fairly level if not slowly increasing. Contrast that with the overall consumer computing market which is notably shrinking, even for Apple. More and more "normal people" are covered with a phone or tablet as their main computing device, which leaves full fledged desktops increasingly to the realm of needing horsepower for specific use cases, such as gaming, machine learning, or content creation. The Mac Pro is specifically there for those who need the horsepower and expansion possibilities to get actual work done on a computer.
You are correct that Apple has not given it significant updates, but that may be explained as neglect or not having significant upgrades from their partners (such as Intel or amd). I'd say its more in the realm that Apple abandoned their focus on this segment to focus on consumer electronics overall, which is a larger potential user base.
Whether or not is is important is a good question. Like I mentioned above, the Mac Pro defines the ceiling of what is possible on the platform. If Apple abandons the Mac Pro entirely, then certain applications may no longer exist - think high end 3d applications like Cad, SolidWorks, or Maya - all of which still only work on ArmMacs via Rosetta. If these apps go away then suddenly there's a creative brain drain from Mac OS, which cannot be good for the platform at large. While the Mac Studio exists, it's GPU performance is not at the same level of what high-end windows workstations are capable of doing.