Answer 1

In battle
Normalize makes all moves used by the Pokémon with this Ability act Normal-type instead of its ordinary typing.

All moves. Hidden Power is no exception; I don't see why it would be.

Because of this, a pure Normal-type Pokémon will never receive same-type attack bonus when using Hidden Power unless it also has Normalize as its Ability.

This is the only way a Normal Pokemon can receive STAB from HP. HP cannot be Normal type except for the Normalise ability, despite it being classed as Normal type in game.

Normalise

Hidden Power

Answer 2

Yes it does

Source: I just tested it on Showdown with JamesBlob.

My Delcatty used Hidden Power [Ghost] on Blob's Gastly, and Gastly was immune to it, meaning that Normalize made it a normal type move, otherwise it would have been Super Effective.

Comments

Or it could've meant it turned into a Fighting type attack. :P

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Normalize turning a Ghost type attack into a Fighting type attack. Seems legit.

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It'd probably be better to test it out on a Kecleon to see what type it changes into, just in case trachy's right. We might all have been wrong all these years. :O

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LOL!!!!

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Hold it. dosen't normalize change YOUR OPPONENTS MOVES TO NORMALTYPE?
those caps are for italic.

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No. It changes the type of all your moves to normal type.