Yes? I'm not sure what you are getting at?
This, (or any other ability equivalent to a 9th level spell) would be available to the Expanded Martial class at the same level that casters get 9th level spells.
I'm not dancing around talking about an ability equivalent to a 9th level spell. I am literally talking about it. (Although hopefully most of the Expanded Martial class's top-level abilities will be more distinct than close copies of existing spells.)