Working strictly with the English language, "he" is correct for all non-female only species of Pokemon.
No, it is not. The idea that "he" in English is gender-neutral is archaic. Will you find style guides that tell you it's okay? Yes. And those styles guides are outdated and have no idea what they're talking about.
As "nitpicky" as people may think this is, TC is totally right. If you're referring to a whole species as "he" or "she", then unless that species really is single-sexed, you are wrong. You don't have to change, but you are wrong.
Think about it this way. Scizor can be a either a he or a she, but NEVER an "it."
That makes no sense. A specific individual Scizor can be a he or a she, but a general Scizor as a species is an it. This is the same as it is for Humans. A general Human is an it; a specific individual Human is a he or she or they.
I usually prefer to call them by their appearance and gender ratios. For example, Big and threatening pokemon I call "He", and Cute pokemon I call "She". The only exceptions are Togekiss and Granbull, which I call He and She respectively.
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