Yes, it’s possible and those instructions are accurate. An Ember app at its heart is two JS files, configuration values (generally stored in the meta tag) and an html element that Ember knows it should render into. Ember CLI makes it much nicer to work with, but that’s the core of an Ember app.
To make life simpler for yourself, you can also adjust the
storeConfigInMeta value to false (see Asset compilation - Advanced use - Ember CLI Guides for details) which will mean you don’t need the meta tag for config info.
Beyond that though, you’d need to work out how to deploy your Ember app JS files to your other system as your Ember app changes. And then you’d need to load the JS files at the appropriate time (or on the right page). But those become standard “I have a JS lib that I want to load here” questions.
As far as getting your other app to talk to Ember (or vice versa), that gets a bit trickier. But it’s perfectly doable if that becomes a need