No exceedingly rare doesn't mean exceedingly random. Two different things.
The randomness has some rules, it' needs to be in certain places.
We need to figure out what these rules are, just as with the UA.
Wait until we find the first one's, then well be able to apply sound logic and common sense to it.
Yeah because it is admittedly "spawned" randomly AND that it is rare that means it is a % chance as of now. That means exceedingly rare would be well under 5% chance. Considering the tons of people out there not finding it i'd say it was <1%.
The fact nobody has found any is pretty good chance there is a bug.. also considering other people have confirmed that using other means. Its just getting them to admit its bugged.
I'm willing to bet we'll see "nope its not bugged' But secretly they fixed it and you'll see someone in the next day or two pop up with a success...