This means GOS is not AOSP either, because it's not that particular project. It takes the Android source produced by AOSP and builds on it. But what you agreed to is just pointless pedantry that leads directly to this outcome, as everyone uses "AOSP" to refer to what AOSP produces (which is a particular flavor of Android that serves as a base to build other flavors on).

It stops being ironic when you take some time to understand that the two cases only appear related superficially, but are actually quite different. You could even say opposite.