<shakes for more detail>
Boeing will likely have to submit to additional certification internationally, and possibly additional retrofits to bring it into parity with at a minimum the same level of redundancy that Airbus is held to (for the EU at least).
Enough dice were cast that it would be diplomatically/economically inconvenient for the EU to lock out the MAX entirely without seriously inconveniencing every other country that invested in building out their fleets with them.
8 ball is not saying that the EU doesn't have the wherewithal to stone wall Boeing, but... somehow more air traffic is likely to be seen as more satisfying to the palate in the long run than any gains to be had by grandstanding too hard against American Corporate Corruption in the short term.
And in terms of criminal liability, that involves stapling the crime to various real people, and proving a case against them.
At a minimum, Boeing is facing potential exposure for: -Corporate Manslaughter -Fraud -Securities Fraud -Criminal Negligence -Product Liability
Those are just the major ones I can think of off the top of my head. There's probably interesting flavors of
-Making false statements to Federal Agents -Perjury
And a host of other exotic crimes players in this debacle can be charged with, if you had an AG with the interest and will to hit them with every reasonably provable charge.
Magic 8 ball says there will be investigations into the part played by executives, getting to the root of who was pushing the deceptive documentation, design, and sales decisions.
They get criminal charges. Boeing gets sued for securities fraud and settles or otherwise pays out.
Civil suits for victims family's will likely be paid by insurer's/the Federal Government (likely pitched as a surprising diplomatic concession, really a National Security concession).
FAA or Congress may surprise and crack down on Boeing, laying down a plan where the executive leadership gets swapped out, mandatory culture/operational revamp under Federal supervision for some number of years. (Boeing has too much National Security impact to have the plug completely pulled).
Mmmm. MAX probably get refits/regulatory waivers of various flavors; pilots/Flight Attendants will be the primary determinant on how much has to get done. Combined Boeing/Pilots/Flight Attendants Unions run a PR campaign, vouching for MAX's safety. Planes return to service, and eventually the public begrudgingly returns to their normal flying habits.
737 line is probably officially on it's deathbed. FAA may see some major scrutiny, and possible budget increases depending on political will.
And the world turns.