just to be clear since you said both again in different sentences, GUID and UUID are two names for the same thing.
I think that spec predates uuid4, it only mentions the time based/node based variants. 122 bits of auth token should be plenty, right?
the sheer unlikeliness of guessing that large a number, the original post is fake or something else is going on.
you can also buy a nice USB/Bluetooth dac instead of the inline ones that tend to be more fragile. better quality than an internal one and the flexibility of Bluetooth if you want it. generally a little bulky but if you already have wired headphones I don't think it's significant