I do have a serious concern about software support in all. OS X as a UNIX was a revelation to new unique software for Mac. Suddenly we had those strange little supporting softwares at our hands to do anything we wanted. For free.
Transitioning Mac Pro users to Apple Silicon is going to be Apple's biggest challenge, but I don't think free Unix/Linux software is going to be the problem. MacOS on Apple Silicon is still Unix and many - probably most - packages already build and run fine on Apple Silicon. Linux and Unix have supported ARM since the 1990s. (OK, ARM64 somewhat more recently...) and they've never been so completely dependent on x86 as Windows. It's mostly open source and mostly written in C or other high-level languages, so if the original developer isn't interested in supporting ARM someone else can step in. Support on Homebrew (package manager for open source packages) is looking pretty healthy: https://doesitarm.com/kind/formula
The more serious problems are going to come from the state of libraries/APIs like OpenCL and OpenGL when Apple Silicon really relies on software being optimised for Apple's own Metal etc. to get decent performance, and even if the standard libraries work they may have lacklustre performance. It's reassuring that what happened with Blender shows that Apple is prepared to pitch in to ensure that key apps get Metal support.
Apple's problem, though, is that as long as they're beholden to staying compatible with industry standards - which effectively means x86 + the GPU manufacturer de Jour, it's very hard for them to distinguish themselves from generic, cheaper and more diverse PC hardware. The Intel Mac Pro has some nice "flourishes" like somewhat more efficient SSDs and MPX slots that eliminate trailing wires and make multi-GPU cards neater, but ultimately it's just an implementation of the Xeon W platform and slightly re-packaged AMD GPUs - a battle over which is the fastest at running Avid (or suchlike) it's just going to be a slow, unwinnable war of attrition against cheaper, more customisable PC hardware - in an increasingly specialised market where moooar powwwwerrrrr!!! at any cost isn't necessarily key.
The current Mac Pro really isn't an economical choice for anybody who doesn't have a heavy, historical commitment to some bit of MacOS-only (or better-supported-on-MacOS) software. In the short term, such a commitment can easily justify the purchase of Mac Pro hardware - in the longer term, one by one, customers are going to switch, go out of business or retire unless Apple can encourage new people in with innovative hardware and well-optimised software that shows clear advantages on Mac.
Back at the 2019 Mac Pro launch it was telling that they didn't offer any performance comparisons with PC hardware - just older (and, by then, rather outdated) Macs. C.f. the Apple Silicon launches where they're dining out on the performance-per-watt stats vs. Intel - and say what you like about the Apple Silicon GPU, it runs circles around Intel's integrated graphics and has seriously raised the bar on what can be done with an "ultrabook" or mini PC.
The challenge is to translate that into clear advantages at the Mac Pro end of the market. The Mac Studio is a great product as a graphics/video/audio editing "appliance" with raw performance to rival the Mac Pro - but it ain't going to replace a big box 'o' slots stuffed with high-end discrete GPUs and insane amounts of RAM. We'll have to see what they come up with.