Sadly no. Unlike Ana and Torb whose costumes were teased the last year and came the next year, Genji wasn't so lucky. Reinhardt hasn't had any luck either, considering he's had an Admiral costume and a King costume teased.
For this year,
-5 characters(Sombra, Doomfist, Moira and Hammond who got a Legendary and Widow who got an Epic) who didn't have a Halloween costume got one this year.
-And 4 characters who did have one(Soldier and Pharah had an Epic, but got a Legendary this year while McCree and Mei had a Legendary, but got an Epic for some reason) got one this year. Admittingly, Mei is a real mind boggle on why they decided her. I mean, they already have Reaper and Hammond with the Pumpkin theme and D.Va is also capable of a Pumpkin-theme Epic skin.
So far, the only characters who don't have a Halloween skin in general are Genji, D.Va, Orisa, Winston, Tracer, Brigitte and Lucio. In terms of Legendaries, that would include Bastion, Reinhardt, Widowmaker and Hanzo. So out of 28 heroes, only 7 of them are missing a Halloween skin and 11 of them are missing a Halloween Legendary skin.
That being said, Widowmaker's Countess/Huntress skins are considered a Pseudo-Halloween skin for her, as she uses the Countess look in the Junkenstein comic and as the base for her sticker look.
Genji, Reinhardt, D.Va and Brigitte also have skins that can work as pseudo-Halloween skins, being:
-Genji's Oni skin
-Reinhardt's Blackhardt/Bloodhardt skins
-D.Va's Black Cat skin
-Brigitte's Shieldmaiden skin(as in the Junkenstein story, Brigitte is referred to as a Shieldmaiden.).
Oni, Black/Bloodhardt and Black Cat can be gotten anytime, but Shieldmaiden, sadly, is Anniversary Event only. And then you could also technically include Winston's Safari skins if you took the term Halloween costume literally. Although it's surprising they haven't done a Jekyll and Hyde skin for Winston yet. And out of the classic monsters yet to get a skin, they haven't made a Werewolf skin or a Mummy skin yet.