Mercy isn't Chancey. Unacceptable.

Bastion can be Porygon.

Dva, in a roundabout way can be Kangaskhan.

I'd prefer Genji be Greninja for obvious reasons, but this works too.

Widowmaker not being a spider made me angry until I saw how cute Ariados was.

I guess Reinhardt can be Golem or something.

What's the pokemon that possesses electronics? That's Sombra.

Reaper is Haunter.

Symmetra as Mr. Mime sort of amuses me, but she needs to be something that really dances. I hate to say Kirlia/Gardevoir, but it fits.

Really not sure what to make Hanzo.

Blastoise as 76 doesn't quite fit, but I can't immediately think of anything better.

And finally Lucio is Loudred.

Am I forgetting anyone that's not there?