I applaud their initiative, but see absolutely no possible way of enforcing it. Takes me back to taking the 'toon out at Potato Patch on the Kispiox which is technically reserve land, approached by a younger local who demanded $35 for fishing on their land. I told him I would gladly pay the fishing fee to the local band if they could provide me a receipt or any kind of legally binding proof of purchase. He couldn't and so I told him I wouldn't give him anything and would go speak to the band in Kispiox about it and that was pretty much the end of it. So perhaps I could see a similar situation where in there are similar self starters looking for easy chump change but I highly doubt they would be able to enforce anything short of breaking the law themselves so I wouldn't get overly worried about the Skeena in 2019.
All that being said, if the major FN in the region were collaborating with the DFO to have it shut down, it may be possible to see the river shut down due to stock concerns ala chinook/sockeye 2018. Unfortunately all it really amounts to is window dressing as others have stated, you can bet the nets will still be out and once the test fishery gets its first spike of sockeye in early summer the armada will be out in full force.