check the mail have from "support@itch.io" and that the link actually sends you to https://itch.io/user/settings/seller/tax-information?retake
If you requested a withdrawal and your tax information isn't valid, then it's normal for you to receive this email. If you haven't requested a withdrawal, then it would seem strange to me if they sent it to you.
Remember that updating your information isn't enough; you must also respond to the email notifying them that you've updated your information. After that, it takes a few business days for them to process the information before they can proceed with the payment and update the information you see on the page (I'm sharing this from my personal experience with my last withdrawal).
If several days go by without receiving the payment, then check the first pinned message posted by one of the administrators.