I feel like the thing you're describing with Lloyd Alexander is also what Susan Cooper was trying to do in Silver on the Tree, except she got it wrong because magic does not equal memory. I would actually have been fine with the Light retreating to Avalon in the wake of defeating the Dark because she takes so much time throughout the series to reiterate how unhuman and incompatible with humanity the Light is, the "cold, white flame". But no, she had to get magic and memory confused and fucked the whole ending.