Question about DJI Mavic Air Fly More Bundle Onyx Black

No, the Mavic Air does not have quieter propellers. The Mavic Pro Platinum (or Mavic Pro with Platinum propeller) is quieter than the Mavic Air.
Other advantages of a Mavic Pro: longer flight time and longer range
Advantages of the Mavic Air over Pro: more sensors (also in the back), partly better camera, smaller mass, etc.
just search for it on Youtube. There are already dozens of comparisons.

In case anyone is still interested at the end of 2019:
Mavic Air +:
- Smaller
- lighter (afaik just falls below a legal guideline, therefore cool).
- Less range (theoretically it doesn't matter, because you're not allowed to fly far anyway and the Air can easily do 200-300 metres. And if you want to go further, you can switch it to US mode and I've already managed 3500m with it. If you want to fly further, you need the Pro). I would have probably also managed 4000m. But somewhere the battery limits you, because you don't exactly fly 4000m in a minute :P

Mavic Pro +:
- Better transmission technology to the remote control
- Better range out of the box
- Has platinum version (quieter in use)
- Better battery

Wait a few more weeks/months. There are rumours that DJI might introduce a successor to the DJI Mavic Pro.... :)