Idea is to allow browser and the rendered application to pass on information available within page elements.

For example - 

<div>
<H1 setvfocus = "true 00:02:00">This is read every 2 minutes</H1>
</div>

The aforementioned code may be flawed, but still will give this idea a shot and hope I am understood.

The reason for allowing this natively within HTML 5 can be helpful as:

1. While the screen reader is voicing stuff at the bottom of the page, every two minutes the virtual focus would read the <H1> heading.

2. We don’t need to set any politeness levels like we do in aria.

3. Simplistic and straightforward to implement.

4. Only issue is whether this is something that can be implemented by API.

The above example can be extended to help keyboard only users as well, especially when focus needs to be set on a text block or a page element.

Something like -
<div>
<H1 setvfocus = "false 00:00:00">Receives keyboard focus immediately</H1>
</div>
would set focus on the heading block instantly, which can be helpful when users activate a link whose target points to a resource on the same page, or a new window / tab.

-Devarshi