Serve --Lab not adding platform specific classes to body

As in the subject, for some reason when I run ionic serve --lab it doesn’t seem to be adding platform-android or plaftorm-ios or anything else. The body doesn’t have any classes for neither iOS nor Android.

Is it just my laptop or you have the same problem? I am on latest CLI 1.3.18 but had the same problem on 1.3.16.

Thanks

No one from Ionic could answer if this is by design or a bug?