Sadly it looks like Victoria 3 only shows you pops at a state-wide level. You can’t see them in just Dublin or Wexford as you did in Victoria 2 (which is much more granular and close-up), now you can only see them in the state of Leinster. Whereas in Vic2 you could see population in like 10 different Irish provinces, now you only see them in a much more zoomed-out 3 states. Instead of having a pop move from Dublin to New York City, you have a pop move from Leinster to somewhere in New York State. It’s a huge step back, if I’m reading everything right.
In many cases it is a step back, but in these examples, it is frankly, not. Truth to be told, the distribution of population within a state in Vic 2 was kinda meaningless. For starter, you couldn't interact with it, all your tools effected state level, not province level. The main thing the population distribution did was restrict where a farmer or laborer could find a job, meaning they had to migrate internally if they wanted to change, but that isn't really necessarily a good thing or a particularly interesting mechanic, all it amount to was the coolness of having more granularity to see where your pops lived, but even that was a bit flawed; You talked about "Dublin" and "New York", but in Vic 2 these provinces didn't really represent the city (actually, maybe NY did, but not Dublin), they represented a huge area around it. A farmer in Dublin might as well be a farmer in Leinster, given they aren't from the city itself.
In Vic 3, meanwhile, altough the pop aren't distributed by province,
their place of work are. You can actually see the buildings on the map, and said buildings have employees. The employees likely live in the same province and, given that provinces are smaller, in a sense Vic 3 has
more granularity than Vic 2.
Which is not to say the system is perfect. I think One Proud Bavaria put it best when he was concerned about the lack of ways to represent minorities regionalisms. Having the population be able to work anywhere in the state solve some weird problems with Vic 2 system but it does sacrifice some flavor and make it harder to represent some situations. That said, I think people see this is a more radical departure from the Vic 2 system than what it is in reality. In piratical terms Vic 2 also dealt almost entirely with states, not provinces, so Vic 3 is just cleaning the system by making it more uniformly state centered, instead of state centered with a few weird exceptions.