Shenanigans!
I'm calling shenanigans on this entire story.
It has NEVER been a thing that updating macOS makes shares on a server running previous versions of macOS unconnectable. I've got clients right now who have servers running Mac OS 10.13 (because that's the last version that Mac OS X Server actually ran on) and macOS 14 workstations. I've got one client still using Mac OS 10.6 on their server (and yes, I've told them to stop, they don't wanna, so I still maintain it, they keep paying me). Uptimes in years can be a thing for those old ones that aren't getting updated any more (and yes, that means they go behind a firewall).
The USB story sounds like nonsense. I'm not saying it's impossible, I'm just saying I've NEVER seen a macOS update break USB drives. Of course, in the old days only an absolute moron would use USB drives on a Mac server, FireWire was MUCH faster and more stable. Today you use Thunderbolt, OWC makes some nice Thunderbolt SSD RAIDable boxes.
The Mac mini was sold AS A SERVER until 2014. There was a server configuration, shipped with dual hard drives to make setting up a RAID mirror easy. They still make great servers for small offices, they're tiny and easy to hide in the wiring closet, you can even mount one (or two if you want redundancy) to the wall. I just installed a M2 mini as a server in a law office late last year, it's been up since the last time I installed an update, ZERO user complaints.
And of course this "Aaron" character decided a homebuilt 'server' was somehow better. I'd call him a moron, but....
This never happened.