As a server engineer this sounds like the correct solution. As someone who runs some blogs, not so much.

If I want to put various formats of images on my blogger.com site (or other similar service) today, assuming some syntax was added to HTML to allow it, I can do that immediately. I don't have to wait N years for the people who run blogger.com to update their software.

This is a problem often run into between sys admins who run their own servers and the rest of use who don't. They forgot that the majority of users don't run their own servers.