I'd say that the USA expidites development of an 18" gun--perhaps firing super-heavy shells. (That is a frightening concept!)
North Carolinas definitely get completed as designed.
South Dakotas are not yet laid down, but with the age of the battle line, some probably get built. (The USA, unlike Britain and Japan, still has a 12" gun ship in the fleet, as well as Texas, New York, and Oklahoma--all with triple expansion engines. Building two South Dakota class ships allows those 4 old ships to be replaced.
Along with the 18" gun, I think that a twin turret would be in the pipeline--a triple turret probably requires a wide enough ship that the Panama Canal is a concern,
What gets built is another story--but the guns get developed at the very least.
Iowas armed with 6 x 18" guns? Impractical, but might get done.