I'm guessing the parent comment is referring to the state of the "built-in" Android apps. Any AOSP app that has a Google app equivalent generally stopped being

I'm guessing the parent comment is referring to the state of the "built-in" Android apps. Any AOSP app that has a Google app equivalent generally stopped being updated when that Google app equivalent was released. The AOSP music player was last updated for Gingerbread (replaced by Google Play Music), Gallery was replaced by Google Photos, the SMS app by "Google Messenger", the Mail app by "Gmail" -- even the Phone app is no longer updated!