I’m more worried that style authors do not know what a UUID is or how to generate one. Version 1 or version 4?
Not even Microsoft’s developer products make people actually generate them. You want a new .NET Assembly, Visual Studio will generate an identifier for you. This only really makes sense if we have a GUI tool that everyone uses and we can control.
The worst and most likely outcome is that people who duplicate styles will reuse the existing UUID, not knowing that you are meant to change it, causing a great many more collisions than currently occur. I would guess the number of times people have created a CSL style that isn’t originally a duplicate of an existing style, in the history of time, could be counted on two hands.
At least with strings that have a slug of the style name in them, people feel like they should change it.