Isn't Evangelion (in)famous for its use of Western religious and occult symbolism? I don't think it's more "Japan" coded than say Death Note (with Western characters) or One Piece (based loosely on Western pirate lore.)
It's more Japan-coded in that the framing of Christianity and the occult is from a Japanese perspective: it views Christian symbolism via an outsider's lens, as an abstract, esoteric ancient cult (which it is, but not in the common way it's perceived in the West)
Also, Eva is much more, for lack of a better term, adult-themed, thematically complex, and sexually weird than Pokemon, One piece, etc. This certainly would make it less universally popular as a cultural export.
Eva is on some level a parody of Gundam used to explore adult themes of depression, isolation, loneliness, parental conflict, and figuring out your sexual identity. It's more like Akira or Ghost in the Shell than it is like Pokemon or One Piece. For an American analogy, it's like Watchmen vs. Superman. Watchmen is a case of taking the kids entertainment of superhero comics and using it to explore more adult topics.
