2 slots? Kidding, aha. ...unless?? No, 2 slots for one tier would be crazy haha. ....unless?!
Anyways, UUBL is a popular tier that many find fun. Even just in the last month we've had like 5 more people join and actively play/discuss the tier on top of everyone else. Will have absolutely zero problem filling team slots with quality, self sufficient players, even if there were 2 slots ($1000 make it happen..?)
Because UUBL is not really played as a multigen tier, after ADVPL excluded it this is the only team tour that BL can have, as there are no BLPL or BLWC or anything like that. So also being excluded here would kinda suck. (Although I'm not tied up to orre, consider this also an argument for orre. I wouldn't recommend knocking either of these for draft specifically, because while draft is immensely popular and I love it, if you want to play in an adv draft tournament, there's certainly no shortage of places you can do so)
Nobody has said this yet, but when asked to elaborate on excluding BL it's often said, so I'm pre-emptively addressing this:
"BL is not an actual tier."
Ok, and?
That's not the fault of the tier's playability, interest, or anybody reading this. Gen 3 just happens to be one of two gens clinging to archaic dataless tiering. Cutting out the biggest Adv Lower Tier in an Adv Lower Tier Tour based on that alone seems silly. Let the people play with the 30some Pokemon!