NDP-4.2, as you mentioned, uses the phrase “are not represented by a Métis government”. The way the bill otherwise deals with the relationship between a Métis government and a Métis collectivity uses the concept of being “authorized to act on behalf of”.
If that text were changed along the lines of “authorized to act on behalf of” as opposed to “represented by”, that would be more consistent with the existing terms of the act. It would not change the meaning that's intended, if I understand the intention correctly of NDP-4.2.