GP Premium includes all of the add-ons in one plugin.
I would definitely suggest purchasing GP Premium over purchasing 5 or so individual add-ons. However it’s not a massive deal as I release updates to the individual add-ons along with GP Premium updates.
GP Premium is coming up on version 1.2.78, while GeneratePress (free version) is at version 1.3.21 (so many versions, I know!).
To answer your question, yes all of your add-ons are working together with WordPress and GP.
Your individual Sections add-on will be updated along with GP Premium 🙂