Tutorial 3: Compiler Option :asset-path has .out file?

[webappzero]

Tutorial 3 explains how to configure compiler options in boot-cljs with a cljs.edn file, named to reflect the js output file generated by the Google Closure Compiler. In the Tutorial 3 that file is main.cljs.edn, with this content:

{:require [modern-cljs.core modern-cljs.login]
 :compiler-options {:asset-path "js/main.out"}}

The present documentation for cljs compiler options doesn't show an example of specifying a .out file as used above.

I successfully tested the Immediate Feedback "dev" task functionality even after removing the /main.out portion of the value of :asset-path such that my new main.cljs.edn file looks like this now:

{:require [modern-cljs.core modern-cljs.login]
 :compiler-options {:asset-path "js"}}

Is there a technical reason for including the main.out file in the asset path? Is it a teaching decision? Or is it perhaps a stale artifact left over from underlying library source changes?