This has been a feature request since Outlook 97 or maybe even Exchange client. Every Exchange customer wants to be able to store and manage the email signature in a way that is consistent in all clients, whether it's Outlook, OWA or even ActiveSync devices. AutoDiscover makes setting up your device to connect to your email very easy, then why is the e-mail signature a client-side feature and is it not stored in the mailbox where it belongs just like message rules and the OOF configuration?
Data Experience Expert (don't know what that is, tried to read the explanation but still don't understand) Chris Woodruff Tweeted earlier today:
I realy wish that Office suite would store things like email signatures in the cloud— Chris Woodruff (@cwoodruff) March 12, 2015
Many people agreed, amongst them was Product Manager for Microsoft's Office Division Julia White.
I find this promising. Microsoft has shown to invest more than ever in the Office products (including Exchange, SharePoint and Lync/Skype for Business) these days, driven by the enormous push to make Office 365 a success. let's hope this feature gets the attention it deserves.
If you agree, please show your support by voting on this suggestion on the Microsoft Exchange Improvement Suggestions website: Outlook signatures saved in Mailbox