No, I'm not sure that's why they changed the law.
But if you think about it, what does native species really mean? It easy to identify some recent imports, especially the "bad" ones. But some definitions of native species mean:
"In the U.S., non-native species are typically defined as those that arrived since the time of European contact"
Do you really want the state of NH checking that every shrub, bush and tree you plant was here before Columbus?
Plus there is this little piece of the definition:
"A species can not be considered native to a particular geographic region or habitat in the United States merely because it occurs natively somewhere within the continental United States. ... For example, a California poppy growing in Alabama would be considered a non-native plant."
So again the state would have to decide if maybe your pine tree from Vermont was Ok but those evil Massachusetts pines were non-native.
The goal of the law is to protect the water quality, not to bring historic purity to the plant world.
Source of quotes:
http://definitions.uslegal.com/n/native-species/