The fishery notice regarding the sectional closure of the Stave River this past fall applies only to salmon fishing, so currently you can still fish there for these winter species mentioned above. That being said, people should be expected not to target spawning steelhead if they are spotted in the channel, just like anywhere else.
The closure of the "spawning channel" was decided back in October when Fisheries and Oceans Canada and the Upper Fraser Valley Sportfishing Advisory Committee concluded that due to the narrowness of the channel and the tendency for fish to stage tightly, it is wise to do so to prevent poor fishing practices such as intentionally snagging fish or retaining fish that are beyond their prime. If we are to close all "spawning channels" in the Lower Mainland, then most of the Lower Fraser tributaries such as the entire Stave River would be closed.
As far as i can read you dont have to have a steelhead tag because it's not a classified water.
If you are fishing a classified water, you will need to purchase appropriate surcharges for that classified water. The classified water isn't necessarily a steelhead fishery. If it is a steelhead fishery, then you need to purchase a steelhead conservation surcharge, just like if you are targeting steelhead in unclassified waters.
The purchase of steelhead conservation surcharge is not determined by whether you are fishing in a classified water or not, but whether you are fishing for steelhead or not.