Edit: There is no bonus content for Days 1-8 (base game).
Yes, if you buy the Endurance version at any point, you'll unlock all the bonus laptop conversations released up to that point.
For now there are 3 bonus conversations that take place, one each day on, Days 9, 10, and 11. When the next update comes out (Days 12-13) if you bought the Endurance edition, you'd unlock the 3 bonus ones for that update and have access to the previous, aforementioned one.
Buying the Elysium Edition ($20) unlocks all released Endurance content as well.