Heck yes it's invasive, it better be for what you want. Way too many people think they know way more than they do about wetlands is my opinion. There have always been species that take over a certain environment until they are knocked back by a natural disaster, whether it's flood, fire, disease, or new competition. Hippy type people expect all wetlands to be frogs and ducks because that's what they saw on TV, or were taught in school. The claim that Reed Canary is not native has been proven false. It is native.
The very best way to establish it, fastest and most successful, would be to find some nice sod that could be dug up, strip the layer with the roots, let it dry enough to break up and spread that layer over your bare area to be stabilized. Spread some moderate fertilizer and water it in. The rhizomes should grow just like rototilling a barnyard full of quack grass once, you'll have a much thicker carpet of quackgrass in a month than you started with.
