As an engineer it is clear the Max can fly safely in almost all conditions when things are reasonably okay given the number of planes and time it has already flown.
A terrible tragedy that at the corners of the envelope, call it a six sigma condition in combination with poorly trained crews and equipment failures and hidden software / automation intervention the crashes occured.

Flying has to be totally safe and understandable airlines will now noodle cancelling, its PR and business combined.

But look at the airlines, the short haul point to point business is exploding, the number of narrow body fuel efficient airplanes needed is crazy, just look at the backlog for the 320 NEO and 737-max are what > 3K and 5K respectively. Airlines that cancel will either stand back of the line at Airbus and likely pay more as Airbus knows what it's got, and wait even longer for deliver crimping the airlines revenue and growth and bottom line businesm

No in the end BA will have a huge egg on its face, get dragged thru the mud, stock will fall maybe even to the low 300s. The engineers there and software are working 7x24 and will produce a solution, the path is obvious
1) Triple redundance to the inputs to the software
2) Realtime indicators to the pilot
3) Sensible over-rides, maybe even more software to automatically suspend the software, LOL
4) Training and more training

I highly doubt any 737-max pilot doesn't now know what is happening when his plane climbs un-intentionally nor what to do, sadly how it became required knowledge is tragic and BA PR problem
BA will be on the hook for years and billions of in liability and class action, will have to compensate billions for the grounded airlines lost revenue, and by next year everything will be in the rear view mirror and hopefully a deep lesson for the AI/software engineers working on driverless cars!