The Invincible class was outside its intended Jutland role

Is it only postwar hindsight that Invincible- and Indefatigable-class battlecruisers should not have fought in the main action at Jutland?

No; prewar doctrine assigned them to scouting, screening, tracking, and attacking ships outside the battle line, so their main-fleet employment contradicted the role Jellicoe himself had described.

The panel says these early battlecruisers were meant to operate as a fast wing beyond the densest fighting, watching through smoke, tracking a retreat, and defeating enemy scouts. Putting them into the main gun battle was therefore not just a later criticism inspired by their destruction. Had they performed the intended role, they might also have made the German escape harder.