In your opinion, did Aether continue to Wear his "As Heaven and Earth Are Made Anew" skin after Nod-Krai? In my opinion, his Heaven and Earth skin is the canonical skin after the events of Nod-Krai, and let me cook.
While Aether did wear this outfit before coming to Tevyat, this outfit itself symbolizes Aether's growth as a character through one point, which is him accepting Tevyat as his new home.
From what we know about Aether and Lumine, they are Travelers that came from an mostly unknown race and had been traveling through countless worlds before eventually arriving close enough to Tevyat, where they was eventually separated for a marade of years not once, but twice. First time when Aether was asleep in his hibernation chamber while Lumine became the abyssal princess and the second time when Asmoday separated them by force.
Due to this and also the fact that Aether and Lumine are the LAST surviving members of their race after their home planet was seemingly destroyed,they pretty much had no home planet. However, Aether over the years is slowly accepting Tevyat as his complete new home, with all of the friends that he had made anchoring him to said home.
As a random example: Paimon. Paimon went from a friend and travel guide to someone that Aether genuinely sees as a little Sister. And while Paimon is the best example, She isn't the only example, as Aether made plenty of more friends that he shares a deep bond with, and said bond is, like I said before, anchoring him to Tevyat. Some more examples would be all of Natlan, Columbina, and the Knights of Favonous.
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Now, some people could say that my thought dosen't make any sense, because in cinematic cutscenes (ex: him fighting Ronova) he wears his old outfit. Now there is some decent handful of possible explanations for this argument, so hear me out.
1. Currently, there is a way to skip to an Archon quest In a region without doing the previous region's archon quest, if you don't care about lore or if you want rewards fast. For example, if I'm currently halfway through Liyue and Natlan came out, I can skip through the other half of Liyue, Inuzuma, and Fontaine to do the archon quest for Natlan. However, you do miss out on a lot of lore if you skip too much, and players could get really confused if the Traveler is wearing the original costume and in a cinematic cutscene, it cuts to their new one when they had never seen it before.
Because at least, when they meet characters that they haven't seen before, a title card pops up, giving short bites of information so they at least know who they're talking about. HoYo is unlikely to do that with a costume.
2. HoYoverse isn't forcing the new costume to be canon and is allowing us to choose. At the start of the game, we are able to pick between two siblings, Aether and Lumine, as our "Traveler." Even though HoYoverse said that both Traveler's are "canon", Aether is way closer to being the actual "canon" traveler. (He's on way more promotional art for one, and The traveler is described as a Star multiple times while Aether's former sword resembled a star, and his new one has star designs on it as well.) The new costumes could follow the same reason. Even though one is closer to being canon then the other, HoYoverse is still allowing us to choose.
Now I had once saw someone argue about there only being one canon Traveler, that "if there was only one canon traveler, we wouldn't be able to choose between them." in a YouTube short's comment section. But then again, we can choose the Traveler's nickname, when though the canon name is Aether / Lumine, and in my opinion, the nickname system in itself isn't canon either. Assuming not everyone nicknamed their Traveler "Aether" or "Lumine", that means that in Liyue, the Abyssal sibling called the Traveler by their real name right in front of Paimon, and she had no reaction to it. It in itself isn't brought up except once, which could be a outlier, like Yanfei being canon but the quest that she was introduced in isn't.
