Why do some sites say Gallade can learn Wish but others don't?

Question

I went in showdown and created a gallade in gen 6 anything goes and saw Wish is available but here in the gallade article it doesn't say anything about Wish

Comments

Not a full answer, but https://bulbapedia.bulbagarden.net/wiki/Wish_(move)

Answer 1

To get Wish on Gallade, you would need to have transferred a specific Japanese event Ralts from Generation III all the way to Generation VI. Pokemon Database does feature transfer-only moves in learnsets, but is inconsistent with transfer-only event moves. This is why there is a dispute between websites whether Gallade can learn Wish, because it can't learn it. You need an old event Ralts with a special move to get it.

Source

Comments

Gallade Cannot learn Wish. But an Old Event Ralts knew that move that's where there's an all out war on if it can or can't learn it