No, the coupon codes will only be given to people who previously paid money for the game (think of it as a roll-over, so no one needs to double-pay). Once my life calms down and I can get the premium page finished up, the first week or so the game is online, it will be on sale for a lower price, and that will be available for everyone.
Edit: If you HAVE paid money for the game, then the coupon codes will be sent to you via the email on your Itch.io account. That's the only way I have to contact customers. The coupon codes are not finished yet and have not been sent. I'll post another devlog when those are out the door, and to announce the release sale.