Could the Invincible class be considered a rebirth of the escort carrier concept?
Short answerMore accurately, it revived the broader cruiser-carrier concept, of which the escort carrier was only the cheapest stripped-down form.
NotesThe broader cruiser-carrier idea was more expansive than its cheapest escort-carrier expression. British prewar thinking sought a ship with enough aviation capacity to support cruiser operations and the forward fleet. That family of ideas includes HMS Unicorn and the light fleet carriers before continuing toward Invincible.