Take the blog article for what you will. I have noticed in Office365, they tend to be less backward compatible than you would expect from Microsoft.

▲ godelski 4 hours ago | parent | next [-]

  > Microsoft swears it's happening

And when has that ever meant it comes without delay?

	▲	stackskipton 4 hours ago \| parent \| next [-]
		Up to you if you believe Microsoft or not. I don't really care, I haven't messed with 365 outside being end user in years.
	▲	dijit 2 hours ago \| parent \| prev [-]
		to be fair with you, EWS has been deprecated since I think 2014, so we're already in the "pushed" window.

▲ ocdtrekkie 4 hours ago | parent | prev [-]

As an on-prem admin, I am blown away that there's 30-40 changes to 365 monthly, often including at least two or three feature deprecations. It seems like building a building on top of quicksand.