Ok, after some digging, from what I can tell is SVG preview’s are not supported at all in WP 4.0 unless previewing on the image attachments edit page. I can only assume this is connected to the ACG image previewing ability.
If you’re running WP 4.0 and try to preview your SVG’s in the media manager do you see them OK?
Also, a colleague did confirm that the data is still being stored and rendered in the front end although the field/preview still says “no image attached”… so it technically seems to be working BUT the preview is not.
