Before Flow 0.223, the autoimport system uses the filename as a hint of the name for default export. e.g. if the filename is foo.react.js or foo.js, regardless of whether the default export in that file has a name or not, or even the default name is bar, autoimport will always import it as import foo from 'foo'.
However, in the new system starting from Flow 0.223, we will use the name of the default export as a stronger hint. In a lot of files that just give a default export a random generic name, they are relying on the old system to get reasonable auto imports.
It's not practical to update every Flow codebase to avoid the UX regression, so now auto-import will provide both options.