So if Alpha zero trashes Stockfish 10 will you be saying, Oh Stockfish 11 sees these as only positions.. Please.
No, I will just be questioning the humans that label these moves as unique snowflakes that no other type of engine could conceive of.
I watched almost all the games with commentaries, I agree with the commentators, the style is definitely unique and not seen before. If the engine could see these they would not get absolutely destroyed.
I don't know what you mean by:
I think there's a huge amount of cognitive dissonance going on, so that people can label AlphaZero's play more 'human'.
or:
if AlphaZero lines have existed at the top of the game for some time.
I think people are overly keen to imbue AlphaZero with characteristics they associate with human play. Stockfish plays lots of alien lines, often relying on perfect defense, that no human would probably attempt in a real game. It's painful and jarring to admit that perfect chess might make no sense to humans, even after the fact. So I think people have emotional reasons to want to call AZ's play more human-like and natural, because it redeems human chess intuition. And to an extent it's valid, AZ is strategically much more sound as you'd expect from it's brilliant evaluation of positions, but it is still powerful enough to play completely inscrutable lines and to accept positions that look plain ugly. And besides, Stockfish also plays some beautiful stuff and newer versions play many of the nice moves we're seeing praised in YouTube videos. Just my cod psychology take, not really a deep point, and not something I'd really argue strongly about.
The second point, I'm saying it's likely some teams, possibly Caruana's have had access to AlphaZero already, and if the public had better access to its analysis we might be able to look at more games from 2018 and see its insights pop up. Certainly some of the lines Caruana played at the World Championship match were strongly backed by AlphaZero in the videos released, but weren't Stockfish's choice, for example.
Anyway, I wouldn't be surprised if AlphaZero lines have existed at the top of the game for some time. Would be a no brainer for someone to have made Google an offer after the first paper.