This is uncommon.
West Virginia income tax is based on federal adjusted gross income determined by existing law at the beginning of the taxable year. If Congress changes federal tax law to exclude certain income from 2020 federal adjusted gross income after December 31, 2019, enter the amount of that income in the space provided. For example, income deducted under Section 199 of the Internal Revenue Code.
You can find more information in West Virginia's Tax Code .