I think there's a lot of confusion in terminology here.

"html5 ad" may mean "videos in formats supported by html5 video tag"

"video ads built in flash" may mean ".flv in our own player", but also "we're going to unpack your .swf and strip anything apart from <run from frame 0>"

Also "From January 2nd next year, Flash ads won't run" does match up with "Google says that Flash video ads aren't included in the cull "at this time.""

The article is pretty confusing though...