Even if certified as "safe to fly"
There are "other issues"
If this ends up type-certified as "Not a 737" (meaning pilots can't just jump from older ones into a MAX), then that's a nightmare scenario for Boeing as it puts them in actual contractual breach with most of their customers and allows those customers to walk away from purchases without paying the 80-90% chargeback penalties that are in the standard Boeing bill of sale.
And that isn't just a matter of "software makes it fly like a 737" anymore either. After all, if Airbus wanted to they could reprogram an A320 to do that.
The issue - as shown by the crashes and the long delays getting it back into the air is that you can make it fly "like" a traditional 737, until it doesn't - and then it REALLY doesn't, so Pilots have to be prepared and trained for software failure.
On the other hand if you strip out MCAS and all the other stuff installed to make it emulate an older machine, ie: making it fly "natively" - then it doesn't fly like a traditional 737 either.
Boeing rat rodded the 737 to make the NG and really pushed their luck. There are handling characteristics on THAT aircraft (particularly around stalling behaviour in the 800s) that would result it from being _banned_ from the air if it wasn't grandfathered on the original 737 certificate - and arguably the FAA should never have approved it, showing how badly compromised they've been and for how long they've been compromised.
The MAX was ratrodding the design well beyond the limits of stability(*) and sensibility. It should never have been allowed to fly and I wouldn't be surprised if something happens like special type certs are issues for existing aircraft allowing pilots with specific training to fly it, but any further builds will NOT be granted certificates of airworthiness
(*) Literally - the MAX is dynamically unstable and the only other kinds of aircraft that are dynamically unstable are intended for aerobatics or combat. Excluding military and actual aerobats, GA or Sport designs that are dynamically unstable end up with severe restrictions applied on usage and no unstable civil transport design has _EVER_ been approved for flight before (it shouldn't have got off the drawing board!) - why do you want an aerobatic bus?
It's a shame that the excellent, but dated original 737 frame has been allowed to be turned into a deathtrap for the sake of profit (airline and airframer). This undoes about 40 years of aviation safety improvements.