I voted OU because no single set or trait of Latias or combination of traits made it Uber by definition
In summary, my vote was largely based on the performance of the suspect from personal experience. A weakness to pursuit combined with a lack of power to deal with Pursuit users which can switch in and KO it does not allow it to act as a persistent offensive or defensive threat throughout a game. Latias suffers from 4-slot syndrome, as CM Latias will always at least lose two of the following: coverage, recovery, or the ability to deal with status, while the Specs version requires good prediction and cannot match the unpredictability of SpecsMence. Its support options are there, but it is either matched or outclassed by other supporters. A great speed tier, stat distribution, and movepool makes Latias solid OU material, but it is not enough to make it Uber.