This is an extension of #1098 / #1343. In addition to import type, Flow has a syntax import typeof. For example (try-flow link):
import typeof { useEffect } from 'react';
var f: useEffect; // has the same type as React.useEffect
Like with import type, these imports are transpiled away and have no effect at runtime, so they should be given the same treatment as import type: that is, they should be ignored.
Currently they're not.
I have a fix which I'll send in a bit.