Aren't they legally obligated to release the source code of whatever GPL software they ship? ie the version shipped that is
This is why most of Android outside of linux kernel is not GPL.
From other discussions, it sounds like they are shipping the copyleft source on time, only the permissive/pushover licensed stuff gets delayed source releases.
By GPL, they're only obligated to release an offer that allows costumers to request the source code. They can still keep the source "closed" by default.