I once had DKIM keys get out of sync with DNS in Office 365. It’s supposed to be handled automatically and that should never happen. Support was as useful as a baby trying to do calculus. It took me 3 days to get the keys rotated and after I understood how it works I realized they should have been able to help me mitigate it right away (dkim keys can be rotated while disabled).
I’ve found that the best trick with Microsoft is: money talks. If you pay them for support suddenly you should have a much easier time getting things done.
Obviously paying MS to fix a problem they caused is abhorrent but sometimes you gotta hold your nose and do it.
It depends on the quantity. MS365 Business Basic/Premium customers are basically testers for the enterprise offerings. Look at release cadences for the different tiers and it becomes obvious.
The only part of the article that surprised me is the fact they actually got the issue escalated. I've never succeeded in doing that; talking to Microsoft support is like talking to a brick wall.