Sailor Moon - that only gained a following from 1998 onwards (there was a short-lived 1995 run which was canceled due to terrible ratings). Pokemon also first aired in 1998. Dragonball Z ran from 1996, but only from 1998 on Cartoon Network's Toonami, which is where almost everyone actually first saw it. So 1998 is the "effective" year that shonen & shoujo first broke in the West. Almost all the translated stuff was sci-fi and seinen before that.
I was specfically addressing the evolution of the English-speaking fandom / American fandom however. Other language groups might as well be on a different planet. American fans hardly ever reference or engage with them. They're not relevant to the argument. 1998 was the year these series became widely avaliabe in the USA.
And yes, a petition was launched to get Sailor Moon back. But the point is that the ratings were still shit. And the petition
failed to get it put back on thr same channel. Hardly anyone watched it in 1995. The people who
did watch it were extra-keen to get it back, but that doesn't mean the ratings weren't, in fact, shit. It wasn't
widely known until after 1998, therefore it wasn't a major influence on the growth of US anime fandom until after 1998.
Actually, summing some of that up.
in the mid 80's you had anime space operas in the USA, fans of those moved onto the 90's cyberpunk / slasher / horror anime film genre, which really culminated in Ghost in the Shell being a cultural point of reference. It's really the peak of Gen-X's involvement in anime fandom.
Then post-1998 you had shonen/kiddie animes for the early millenial gen, which evolved into a demand for "edgy" series with "symbolism" shit airing and being popular with that generation around the mid-2000s (FLCL, NGE, Elfen Lied etc). This culminated in the massive cultural force of Death Note.
Around the same time
that stuff was peaking, the next-gen shonens hit for the younger millenials: Bleach, Naruto, One Piece. By the previous theory, about 7 years after
those series hit that new generation would be ripe for something "gritty and edgy" with gore and/or people's heads exploding, "plot twists", teen angst, symbolism and deconstruction. Cue the market going gaga over Mirrai Nikki, Tokyo Ghoul, Psycho-Pass etc. Attack on Titan's massive fanbase seems to be the peak here.
And about the same time
that bunch of teen-angst "whoa" fiction was big, Sword Art Online aired. Now, if you say a generation is 15 years, then SAO would be "generation Z's" pokemon/dbz equivalent. And that
totally fits. SAO is shonen plus "cool" gaming/internet culture, totally stuff of Gen-Z. "My Magical smartphone" is also tapping into this vein. By this theory then around 7 years after SAO aired you should see the next-gen "thing we all hate that teens seem to love" at the same time as the next "edgy, whoa, did that guy's brain just explode?" wave of popular series.
I there might be something in this cyclic idea. e.g. sometimes animes come out that
should be classics but they get overlooked for some weird reason. Perhaps it's because of a generational cycle of tastes. e.g. Ergo Proxy could have been much more famous if it came out when the right generation of people were looking for something like that.