Yeah, I mean in Johan's first WWW video you can clearly see that if Britain wants to build a battleship in 1936 (before any naval techs are researched) then it will be a Queen Elizabeth-class. Unfortunately, this means that not only are the five Revenge-class battleships lumped in with the QEs - as they were in previous games, and that was fine because they were very similar - but now the Nelson-class are as well. This is totally unacceptable; they were built in different eras to radically different designs. The US naval techs will certainly suffer the same fate.
We know that from (IIRC) yesterday's 2-hour stream that France will be building Bretagne-class battleships in 1936, as there is no model to represent anything designed between those and the Richelieu-class... which, bizarrely, are an entire tech behind the contemporary Bismarck-class (1940 BB tech).
Unfortunately, whilst other complained-about elements of the game have since been addressed (i.e. they completely re-did the industry/supply system AFAIK) the naval setup has not, and so even though adding an inter-war naval tech to represent most of the 'treaty battleships' would have been fairly straightforward (and please don't accuse me of not knowing what I'm talking about... in the grand scheme of HoI IV's mechanics, this really would not have been a major change) addition, it hasn't been done. This means that 90% of the battleships that exist in 1936 (which are the vast majority of those used during WW2) cannot be represented accurately, as everything from 1905 pre-dreadnoughts to advanced 1920s battleships like the Nelson and Rodney are going to be lumped into the same tech group.
Given what an amazing job Paradox have done overhauling and improving so many aspects of the game, sadly it looks like the navy has been overlooked yet again.