Modern nation states are political creations and haven't really existed for all that long. As a creation under the BNA Act, Canada really came into it's partly legal existence on July 1, 1867.  I don't think the 150 celebrations in any way implies that the indigenous community did not exist prior to that.  But I suppose it brings up historical hurts for the many lies and manipulations that were visited on the various nations over the history of this country.