Damn you're right. I was moreso talking about the GP but diplo seems even less likely as it's locked behind so many walls of DLC that few players would know what it is.
Then, assuming that we're 100% sure about the CH, IZ, HS, and Harbor not having the UB, it would have to fall in the Campus or TS. My last idea would be that maybe it's a unique university to reference Henry the Navigator's famed school. Maybe when you build it you unlock cartography lol. But I'm really spitballing here and a Campus UB wouldn't have great synergy compared to a market or something. But watch-the university probably looks the same too and I just missed it in the trailer XD
If they really are going with 2 UI (Which I still think is weird) it's a must that they'll have a unique fishing boat improvement. I mean, who's gonna be getting all that bacala?