Ok, so here's what I've got from reading up on Tlön. Which by the way, is one of the most obscure freakin' pieces of work you could choose to reference as there is almost nothing on the interwebz that isn't heavy heavy philosophy.
Here we go:
The book is essentially about a guy, who reads about a mythical place and that place soon becomes his reality, even though it's completely false.
The flip side to this place being mythical (and completely perfect I might add,) is the founders of the world, who have in secret for centuries been creating the place, have their ideas released to the public in small tidbits, one by one, until eventually, Tlön becomes the world to everyone, not just the subject of the story.
We can take this as: Gruden started as a myth and has become reality OR Gruden was always a myth in our heads and Bubba & company pulled off the biggest troll of VolNation.
It's really a 50-50 split. Though, it coming from Bubba who has been very pro-Gruden, working in the background kind of guy, I think he's implying the former, but again, it could be trolling.
Edit: I've edited some of this to make more sense/put more commentary.