It's not a matter of "becoming AAA to me".
That's just not how it works.
It's based on the number of employees, the coordination involved, and the budget, as I've said. The numbers involved to really be AAA have been steadily increasing.
I don't know enough about the budgets and development of BG1/2 to speak on those, but as of Mass Effect, certainly Bioware were making AAA games. KotOR was borderline - we don't know the exact budget, it's estimated at $10m, which would put it at the very low end of AAA for 2003. Whereas we do know for Mass Effect 1 - that was $40m which was actually a fairly high AAA budget for 2007.
Uh-huh, but you're very confused, so that needs to be fixed.
Paradox Interactive are a publisher. They own several studios, including Paradox Development Studio (PDS), Harebrained Schemes, Triumph and a bunch of others. You're conflating Paradox Interactive - the publisher with Paradox Development Studio, who the people who actually make games.
PDS make the games you think of with Paradox - EU, HoI, CK, etc. - They have 150 employees, not "more than Larian", who have 400. So absolutely you are wrong. You're confusing the numbers of people in ALL the studios the publisher runs, and at the publisher itself with the actual studio.
It's similar with the other examples. Ubisoft is a publisher. It doesn't make any games, it publishes them. Various studios owned by Ubisoft, some of them with Ubisoft in their name, many without, make the actual games here's a list -
List of Ubisoft subsidiaries - Wikipedia
By Bethesda, I presume you mean Zenimax? That's what most people call Zenimax and Zenimax prefers it that way. They're not even a publisher, they're a subsidiary - of Microsoft. Zenimax owns multiple studios, just like Ubisoft and Paradox Interactive. Zenimax owns id games, Arkane, and a bunch of others - perhaps most importantly, Bethesda Softworks, which is what Zenimax likes to hide behind, branding-wise. Bethesda Softworks is itself a subsidiary which has only one studio (it briefly owned two a while back), Bethesda Game Studios - That's the Elder Scrolls/Fallout/Starfield people. They have about 420 employees right now, so are almost exactly the same size as Larian.
What seems to be confusing you here is that Larian are a private company and not a subsidiary of anyone. They don't have or need a separate publisher.