AWS is losing market share to Azure and Google (slowly). It's very silly to say Azure is a dead-end while it is one of the largest growing revenue streams for Microsoft. It sounds like this person was perhaps in the Silicon Valley reality distortion bubble and smoking their own exhaust fumes. Perhaps they should spend time out in the real world.
Not much would be my guess. The businesses in the are not exactly the staples of industry and the economy. Would it suck? Yes of course. But it wouldn't make a ripple in the overall market IMHO.
The one thing it could do is bring additional scrutiny to other "unicorns" books as bring them down to more realistic valuations.
the key word is "like". I certainly wouldn't mandate moving the customer to 365 just for this. But chances are they are already using something "like" Office 365 or Google and have already done the Idm integration.
Why try to implement SAML yourself when you could more simply integrate with something like Office 365 with OAuth and let them do the SAML integration with the customers Idm system?
A good book that includes a lot about John is "Into the Black" about the shuttle program. He was commander of STS-1 and was heavily involved in the program.
With a bus/truck they remove the bodies (usually). These ships went down with people in them and are graves. There is a difference.
It would be like you being buried in a coffin in a stone church and then one day someone decides they want the stones and they take the whole church ... including you :) As a relative i would be pretty pissed about that too.
If they were correctly identifying bodies and returning them to their families for proper burial etc... then it might be ok to reuse the steel.