A 1980s naval war teaches only through its specific losses

How would warship design have changed after a major naval war in the 1980s?

It depends on the belligerents, losses, and proven doctrine, especially whether the war came before or after navies had absorbed the Falklands evidence.

A major naval war in the 1980s does not produce one predictable generation of ships. Designers would respond to the combatants, the weapons that succeeded, and losses such as British, American, or Soviet carriers. Timing matters because a conflict before the Falklands War begins from different assumptions than one fought after its lessons. Even within the later period, conclusions drawn in 1983 would differ from those reached after several years of analysis by 1987. The useful counterfactual must therefore specify both the campaign and the doctrine being tested before it can predict design change.