>>33910006They only consider the gender of a pokémon in the anime as canon if they're explicitly referred to as male/female in the japanese version, or if they're affected by Attract used by a pokémon whose gender is confirmed. A pokémon naturally falling in love with a female mon or being called a he in the dub doesn't prove they're male.
And since neither of those criteria apply to Ash's Charizard, they list his gender as Male* (*Games ONLY, because when a Charizard with Ash's OT was given in events, his gender was male).
