We need yet another completely different inferior product called "Outlook" to support like a hole in the head! Why do Microsoft keep doing this? Onenote windows 10 app/ 2016 all over again. How about actually finishing feature parity in the *NEW* mac client first or the *NEW* Exchange admin console or the *New* Teams client before you start on releasing another thing with half the features missing.
The Compliance/Security/Office 365 security console/Exchange Admin console is a total mess right now of things that tell you they are sort of deprecated and have to go to some other console and there are many mail related things that you can do in the office admin console that you cannot do in either version of the exchange admin console - such as controlling sent item behaviour on shared mailboxes and being able to turn smtp auth on or off in the app settings.
Microsoft just get bored and keep re-inventing the wheel.
And 2 and a bit years on, we are no nearer to seeing roaming cloud signatures in outlook - this is what happens when you don't work together as just one Exchange team on the product.