Von Reddit: https://www.reddit.com/r/swtor/comments/3au8xm/lady_insanitys_breakdown_of_the_e3_kotfe_demo/

Dauer und Umfang der Demo

In the demo I saw, the devs skipped a lot of the gameplay between the escape/Tanek and the Sun Generator (for time's sake, I was supposed to be there only for 30 mins but we stayed a bit longer). It also felt like there's more to play after your escape - the chapter doesn't end there. There's a lot to the first chapter that we didn't see.

Die Demo dauerte 30 Minuten, Kapitel 3 war danach noch nicht zu Ende.

Wenn man den Ausfall des Sun Generators riskiert

From what I understand, a consequence to not helping the sun generator. While you skip over it now, you'll end up with dirty work later that light side doesn't get.