Since Ilmater and Tefnoor are travel advisors for andalites visiting Earth, do they ever have to interact with human-nothlited-yeerks (or advise their clients on how to interact with them)?
Disappointing reveal time: there aren’t any Yeerk-to-human nothlits in their version of postwar Earth! If this were my AU where Aftran become a human nothlit, maybe the situation by the war’s end would be different enough that other Yeerks would also be able to choose that fate. But Tefnoor and Ilmatar exist in my interpretation of postwar Earth according to canon, where Aftran is a whale and the intergalactic political climate probably wouldn’t allow Yeerk-human nothlits at all.
I have a soft spot for the Yeerk Peace Movement, so I like to imagine that former YPM Yeerks (and Yeerks who cut certain deals with certain people) would be given the option to nothlit as cetaceans instead of getting sent back to the Yeerk homeworld. Yeerk nothlit whale-watching tours could be an extremely lucrative business, if the threat of anti-Yeerk violence wasn’t so high; as it is, the nothlit pods’ migration patterns are kept confidential for their safety.
Just because Aftran and her peers are living off the grid doesn’t mean they’re completely out of touch with Earth culture, though. Tefnoor has a human-style hardcover copy, with paper pages and everything, of Aftran’s bestselling and highly controversial memoir. It holds the record for being the first book written (via thoughtspeech dictation) by a humpback whale.
(Those rumors that certain Yeerks and voluntary hosts with especially valuable scientific and political expertise have been allowed to remain as they are, under new identities, in exchange for their knowledge? Those are just rumors. Just ignore them.)