Thanks for the comment! That part should be refactored to make it less confusing.
Short answer: no ☺
It just says that you don’t have to put your main application files into separate directories, but if you do that you’ll have multiple main() function definitions in the same location/directory. This will 'break' 'go get' because it will try to build all code in the directory you referenced, which will fail due to multiple main() function definitions.
If you have separate directories for each main app file then 'go get' will work and 'go build’ will work too.
If all your main app files are in the same directory then 'go get' will not work, but 'go build' will. This isn’t a deal breaker for most go applications because using 'go get' to install applications is not that common. It just means you’ll need to clone the repo first and then run the build command to create an executable for the app.