No, if Maryland is requesting verification of your 2017 income, this will not affect the processing of your 2017 Federal Tax Return. Your Federal and Maryland Returns are processed independently of each other by the IRS and Comptroller of MD.
However, Maryland can offset your Federal Tax Refund if you have outstanding taxes owed to them. As long as that is not the case, the processing of this year's Federal Tax Return should not be affected by Maryland's review of your Tax Return.
