figure role backgrounds

Hi.

I'm trying to find a background information about figure role, where it
comes from and what is its use case. I was able to find couple email
threads on svg-a11y [1] and aria [2] mail lists, but they don't give much
info. Rich said that the figure role comes from SVG needs:

We need this for SVG Accessibility as we need a mechanism to isolate
figures that could be pulled into a list of figures by assistive
technologies.

Since ARIA role='figure' replicates HTML figure element, which doesn't have
UI and is basically a pure semantic element, then I'm curious whether this
element can be reused in SVG world.

What is criteria for introduction of a new role/feature in ARIA that copies
semantics of a HTML element?

Thanks.
Alex.

[1] https://lists.w3.org/Archives/Public/public-svg-a11y/2015Aug/0028.html
[2] https://lists.w3.org/Archives/Public/public-pfwg/2015Oct/0023.html