Would the 5-inch/54 have prolonged Atlanta production?

Would Atlanta-class cruisers have been built in greater numbers if the 5-inch/54 had arrived earlier?

Yes; the larger gun's range, power, and cruiser-scale installation would have differentiated Atlanta enough from destroyers to strengthen its procurement case.

Atlanta's historical 5-inch/38 battery competed directly with destroyer armament. A sufficiently numerous 5-inch/54 installation would have offered more range and hitting power. Its size would also have made a large battery much harder to place on contemporary destroyers, reserving the capability for a cruiser hull. The comparison echoes Dido's 5.25-inch battery, whose distinction from British destroyer guns helped preserve a separate role.