Wichita follow-ons would not be quite similar to the original vessel. She was deemed too unstable and to have wasted too much weight in terms of displacement. some modifications would have been made.
Helena's class had known similar issues, and it was not desired to repeat them.
The projected timespan increase for a new design, in 1939, was only 12 months, bringing it a total of 48 months for a new design to correct past issues vs 36 months to continue construction of existing ships. Given that both existing cruisers were seen as outdated and had known issues, there'd be a redesign as it is to take advantage of the lack of weight restrictions. They might look different and be less capable than the OTL cruisers developed, but they would be an evolution of previous vessels, not repeats.
The
Alaska class, if design was rushed forward, could evolve in a myriad of ways. It possibly could be used as a slightly smaller 3x3 12" cruiser, but with otherwise better armor. It would seem even more wasteful than OTL considering that it'd only be a few k tons lighter and at the same time having only 67% of its firepower. It may be reduced to a super heavy 8" gun cruiser with 12 8" guns and be lighter. It could end up as one of the CA2 series (even up to CA2D, but that seems unlikely). Heck, it's remote, or you could see the 3x2 12" be remade as a 3x3 10" - the 10" gun was considered, but often not favored. Part of the reason for the
Alaska getting more and more barrels is due to the belief that she was underarmed for her size. The 10" gun cruiser, with some armor reduction, could come in thousands of tons under her with the same number of barrels.
Or it could be cancelled. But that is boring and wouldn't trigger ursines

Seriously, though, the
Alaska design wouldn't be finalized until well after the PoD.
I would have to wonder, considering the higher battleship focus, whether any of the
Montana (Whichver design is chosen) are laid down and if any would be finished, or if they'd be inevitably cancelled.
Also, considering the need, there is a decent chance that an
Iowa or
Alaska or etc gets sacrificed for a conversion to carrier. Assuming that a Pearl Harbor happens, which it won't.