Is there crossplay?

Yes there are at least two instances of this:

-Bloodhound is often assumed to be a male at a glance but strictly speaking the gender of this character is never referenced and the voice over is done by a female. A mystery like the Pyro from Team Fortress 2 or Birdo from Mario.

-I also got one of Wraiths legendary skins which made her look like a boy who has been sectioned while getting hit hard by withdrawal.

They tried too hard to push Bangalore as a tomboy to the point that it dominates her identity but I wouldn't really say that counts.

Oh wait you mean can we play together regardless of platform? No. At least not right now.