Do you thing the MPP Fly More Combo will go on sale like the regular Mavic Pro did when then MPP came out, or is the Mavic Air gonna be its own "class" of drone and all pricing stays the same?

Looking at the specs for the Mavic Air - it looks more like a product that will fit above the Spark but below The Mavic Pro / Mavic Pro Platinum - so, IMHO, pricing for the existing Mavic Pro line will not decrease.
When Apple introduced the MacBook Air, it was a less featured (but much thinner and lighter) and lower priced MacBook.  As DJI seems to align itself with much of Apples Marketing, I’d bet this is the DJI plan for the Mavic Air.

As always, Your Mileage May Vary.

Looking at the specs Mavic Air price point is 699, so I doubt it will. But I’m only speculating.