Drywall does not make contact with every piece of framing behind it firmly. Crews that do drywall have their screw guns with the right torque for the screw to go in and fasten to the wood, not pull the drywall to the wood. So yes most fasteners will have the drywall tight to the framing but not all.
You also need to think that not every piece of lumber is straight. So your wall will have very slight waves because of this. I strictly have my guys frame with the bowing going outward. Drywall is pretty flexible to account for this.
That being said I don't like lips on the bottom and top plates. This is because while drywall is flexible it is a bit to ask for drywall to flex a lot in just 2" span. Yes you could easily screw it in without overfastening and leave it straight but that is a bit of an art.
The other issue with the bottom plate is the installation of trim. Screwing and more than likely nailing into the bottom plate will be more difficult with a gap.
Your framing looks a lot like the framing I get from most of my crews. I would normally spend 5-10 mins at the end going through rooms with my mallet (hammers dent and splinter easier) and tap things flush and draw big blue lines where we need blocking in the corners to hang drywall.