Postwar cruisers tested the next fleet

Were the Tiger-era cruisers essentially postwar experimental ships?

Yes; modifying available hulls let the Royal Navy test ideas and retain design knowledge while postwar budgets delayed an entirely new cruiser.

The postwar cruisers became experimental steps toward a future design. The Royal Navy had learned rapidly during the war while continuing to build ships under immediate pressure. Once peace brought budget cuts, existing hulls offered a way to test radars, automatic weapons, electrical systems, and reconstruction methods. The work preserved design knowledge so that a better ship could be ordered when funding loosened again.