No, they are about safely adding capabilities to the web that native apps have. Home screen icons are only one of those capabilities, and not the most important.
PWA is in fact a corporate born, bred and sponsored definition created to push and promote an _arbitrary_ set of Chrome features. It was an attempt to build momentum towards a vision for the web where browsers can run "open" apps. Unfortunately visions don't die, and thus the term lives on. Sigh.
