I think this is not correct. According to https://en.wikipedia.org/wiki/Web_application, Web applications are applications running in a Web browser. The term was introduced to distinguish Web _apps_ from Web _pages_, not to distinguish _Web_ apps from _native_ apps.
> Web applications are applications running in a Web browser
And Electron embeds an instance of Chromium, to provide a webview for the 'application' interface.
How is that not a web app? It's written in HTML, CSS and JS, it runs inside a browser.
Just because the user can't choose the browser doesn't mean shit. Users couldn't choose the browser to run a lot of Microsoft-stack Web Apps in the early 2000's either, because they only worked in MSIE.