From what I'm seeing it's more likely a split in interpretation from settler Canadian government understanding vs. Traditional sovereign understanding, plus the fact that there are multiple territories/reservation communities with their own hereditary chiefs, and possibly also the difference in definition for what constitutes a chief/hereditary chief.

I could be off on a few details so best to ask directly if you can find Wet’suwet’en elders, but from what I know about the region there are elected governments that Canada recognizes and conducts it's affairs with -- that were mandated and sort of set up by Canada's government and required by Canada's government (but not necessarily genuinely agreed upon by the First Nation in treaties especially since Canada has failed to uphold all of its treaty agreements with indigenous people) in order for the reservations/territories to be held, so you wind up with situations where it's just a puppet government of sorts that depends on the Crown etc. but handles "officially"recognized affairs.

Plus remember that nations like the Wet’suwet’en whose territories originally span larger geographies than what they're relegated to today, so there may be multiple locations of reservations under the same nation. Maybe some "ceded" (a term supposedly favored as a negotiation tactic for sounding the same as "seeded" to obfuscate surrendering land to the settler governments in the treaty talks; which even then because of treaty violations, the territories are technically supposed to go back to the Wet’suwet’en) and certainly there are territories that remain unceded (never surrendered).

And then there is traditional government where the people adhere to sovereignty on their own pre-colonial terms and identity--where clan systems, community consensus, etc. remains the center of focus.

Often in treaties there's a very crude assumption that chiefs/hereditary chiefs always = king/president/governor/mayor etc. by Western colonial assumptions when in many First Nations they actually have chiefs as a sort of elected project manager/diplomat, and sometimes they are specific to clan roles but are accountable to the entire community and/or elders/grandmothers.

So you may hear there are people from the same First Nation who have accepted agreements with Canadian government and the oil company. Especially with the amount of money and resources that goes into these giant infrastructure projects between the pipeline/fossil fuel companies and Canadian government, press releases etc.

And at the same time there are people who are also technically identified as under the same First Nation by heritage and identity that oppose the pipelines because it's a continued violation of the original Treaty agreements, their ongoing sovereignty, and for some nations even their obligation to the land/earth (e.g. as part of their creation stories/governing protocols etc.).

From what I'm reading so far, this is the dynamic at hand.

Read a less industry oriented source or see perspectives in r/Indiancountrytoday and you'll probably hear more of the latter and see the distinctions. Here's a recent article with a Wet’suwet’en hereditary chief who's opposing the pipeline and defending territorial sovereignty and their laws that runs in stark contrast to the Post article from OP: https://indiancountrytoday.com/news/police-move-in-on-wetsuweten-territory