Though Ikkyu had his satori, it's only the beginning of the journey. The spider of doubt chides him for going to decadent Kyoto and hanging onto distinctions, perhaps the way Ikkyu ends up in the end was his way of defeating it...
Also I believe the robe quip he gives is one of the elements of his life that survives on in Japanese folk stories, same as the stories of his childhood with the folding screen tiger and so forth.
Also I knew the author died after finishing this, but I didn't know it was only 2 weeks later, feels poignant and I'd be glad to read more.