QML Import No Longer Uses Path

After updating from Qt 5.12.2 to 5.12.4 many of our QML files failed to load due to type errors. After investigation we discovered that these missing QML types were present in the qrc file system, but not defined in the qmldir.

Was this an accidental regression? We are going through to add all QML files into the qmldir, but based on the documentation we understood this should be supported and imports should resolve within the file system if not found in the qmldir.