Honestly the current Mac Pro was kind of a joke. Same CPU as some Mac Studio model that was like half the price. RAM is soldered on so that's no advantage of the tower. It's got storage bays, but nothing to do with them since the storage is soldered on and no SATA or M.2 slots. The PCIe slots are there, but almost useless in macOS (since you need macOS ARM drivers and there just aren't that many of them. I will note, if you throw Asahi Linux on one of these, the PCIe is fully useable, since the Linux drivers are portable including to ARM systems. Even apparently the unnatural combinatoin of ARM CPU + Intel ARC GPU.) Apparently the one advantage of the tower is it's SLIGHTLY faster under extended full load operation (due to better thermals), but for the $1,000s in price difference once could have likely just pointed a fan at the Studio to make that up too.
To me this article is pure Apple fanboi'ism... like... Apple makes non-expandable systems, therefore everyone will switch to this.
There's those "Chromebook-based" systems where they've got some wheezy bit of RAM and SSD (sometimes a nice slow eMMC) soldered on, of course. But Intel has now announced "Lunar Lake" (which had RAM integrated on the CPU) is a one-off and they are not doing that any more, so that appeared to be a sign of this kind of trend, but Intels stepped back from doing this.. Anecdotal of course, but my mom got a notebok for $218 new recently (due to RAMpocalypse it now costs about $250). I really assumed (since one of the vaunted reasons for soldering on is to save the cost of the DIMM and M.2 slots) that it'd be a Chromebook-style board with everything soldered on. Nope! There's an access hatch at the bottom of the case, and it's using conventional DIMMs and M.2.
I don't see notebooks going all to "let's just solder it all on"; and desktops I DEFINITELY don't see this even starting to be a trend outside the Apple world other than perhaps the smallest systems (the ones that are basically a laptop motherboard just in a little brick-shaped case with no screen or keyboard rather than a flat 'case' with a keyboard and LCD built on). Any suggesting of SERVERS doing this is kind of a joke IMHO.
I do have a thunderbolt port or two on my desktop... but, I've never used it. Nothing against Thunderbolt, it IS amazing technlology. But, I added additional USB3 connectivity using a PCIe card, GPU via PCIe card. If I filled my M.2 slots I could add a card to add more M.2 storage too (although, to be honest, I have the vast majority of my storage in the form of spinning rust. I mean, 24TB of storage for maybe ~$400 over the last several years, even pre-RAMpocalyipse something like $2000-$3000 in SSD storage and now probably closer to the $4000-$6000 range.). In that vein I could also use those PCIe slots to pop more SATA ports for even more disk storage LOL.