Re: dominate corporate email client is Outlook.
Recent versions of Outlook at least give you the option to set OOO in advance so you don't forget about it, but I can see the attraction in an automated link between them. There are, of course, issues with automating that:
1. I tend to customise the OOO message to say when I'll be back and who to contact in my absence; hard to automate that.
2. Away from office might mean working from home, or at an all day meeting where setting out of office might not be appropriate or required
Certainly seems like it would be worth exploring, even if it's not the default option to have it enabled.