If you look at the repos in https://github.com/apple-oss-distributions and their commit messages, that is pretty much the definition of the "Throwing it over the wall every so often" approach to open source.
At least the name-brand projects like Webkit and Swift (which have logos and everything) are on a different planet to that.
Yeah, which is a totally valid approach under the GPL, and essentially the closest one to how source distribution would’ve worked at the time the license was written (software disks either come with source code or instructions to acquire it).
For certain use-cases, this approach is actually _more_ convenient, i.e. supporting old platforms. If I'm trying to build a modern piece of software on Tiger, but it turns out I need to first back-port cctools from Leopard, they've made that task extremely convenient for me.
At least the name-brand projects like Webkit and Swift (which have logos and everything) are on a different planet to that.