'The tools for writing apps that write other apps are also showing up in various programming languages, like Go'
That link is a facility Go has added for running tools like Yacc as part of its build process. Yacc is 40 frigging years old and was old hat then (Yet Another Compiler Compiler). The facility is only necessary because go manages its own build process; if you were writing C it would just go in your Makefile.
The long standing existence of tools which generate code to a programmer's specifications is ummm really not a good argument for most code being 'written by AIs' in the future or whatever they're yammering on about.
Note how stuff like this is always 20 years in the future, by the way? In 20 years' time it'll be 20 years in the future too.