No, if you have never lived or worked in Flint, then you would have no reason to file a return there unless your employer incorrectly withheld city taxes and you need a refund. If this is the case, have your employer update your residency information.
The City of Flint, by ordinance, collects a local income tax of 1% from residents and 0.5% for non-residents who work within the City.
Flint Michigan Income Tax Forms and Filing Page
