UUBL is a banlist for the UU tier, which essentially means that, if a Pokemon is in UUBL, it can only be used in OU, regardless of if it meets the usage threshold or not. If a UUBL Pokemon does ultimately reach this threshold, it will rise to OU. If it is slated to drop from OU, it will go back to UUBL unless UU opts to retest it (such as in Aegislash's case). This also applies to any subsequent lower tier and their respective banlists.Is there any chance Weavile will officially get into OU with its current rise? I'm not really sure how tiering works between UUBL and OU.
We can't accurately predict whether or not Weavile will rise to OU from UUBL until it actually happens, but given its rising usage as an incredibly powerful Knock Off user and general purpose wallbreaker with its phenomenal attacking stat, STABs, and speed tier, I wouldn't be surprised to see it rise whatsoever.