I've been meaning to comment on this thread for a while, going all the way back to the discussion of early fish being uncommon. While early fish are harder to come by, most years they are definitely still around. I pulled my journals starting from back when I started keeping them out of curiosity (like others have done). I'll do earliest winter steelhead landed, followed by number hooked for all of December (IMO number of confirmed winters hooked is a more accurate representation of how many fish were around, as my landing rate varies year to year).
2011 - Dec 3 (1 doe Sproat) -- 10 steelhead hooked December -- Vedder had 5 steelhead (4 landed) in 7 trips
2012 - Nov 29 (1 doe Sproat River) -- 12 steelhead hooked in December -- 1 Landed on the Vedder Dec 26, 2 Vedder trips
2013 - Dec 3 (3 landed winters - Sproat and Stamp) -- 12 hooked in December -- 1 Landed Vedder Dec 26, 2 Vedder trips
2014 - Dec 5 (5 winters - 3 landed - Sproat) -- 17 hooked in December -- Didn't fish the Vedder that year
2015 - Nov 18 (1 doe - small west coast stream) - 7 hooked in December -- Fished Vedder twice and skunked
2016 - Dec 19 (1 buck - Sproat) - 6 hooked in December -- Fished Vedder three times and landed 1 Dec 27
2017 - Dec 7 (1 doe - Small west coast stream) -- 7 hooked in December -- 1 trip to Vedder skunked
2018 - Dec 9 (1 Doe - north island) -- 10 hooked in December -- No Vedder trips
That brings us to this current season, 2019. I haven't touched, or even seen a steelhead yet (besides the one single dead one hanging on the board at the clubhouse when I went to look). I haven't actually fished the Vedder yet, and only did 3 days on the island, but from the information I've gathered over the years, and the conditions I encountered, I should have at least had a chance or two. Keep in mind that I've also built up a fairly big network of anglers (good rods), who I talk with regularly. I've heard of a grand total of maybe 8 island fish total in the rivers I frequent. I've heard of 5 Vedder fish (including the ones weighed in at Fred's/clubhouse).
One thing to think about - a vast majority of this years return would be the fish that were residing in fresh water through the 2015 summer (the year that rivers practically dried up, were very warm ~20+C, and got closed). They would have also encountered extremely harsh conditions going out to the ocean in the spring of 2016 (the blob). It's really not surprising that this year is panning out this way. I'm assuming next year will be very similar. Hopefully there are enough fish coming back to spawn to maintain stocks at reasonable levels until ocean conditions stabalize.
While I see the logic behind cutting early brood, I'm not sure I agree with cutting it totally. You do kind of want to maintain all portions of the run. Maybe put a cap on it - something like 5-10% of the total brood fish. You could also go the route of only collecting brood below tamihi bridge as others have said. One positive of getting more fish from the mid or late run is that it would be easier to spawn them all closer together, and therefore easier to size match/grow them.
One thing I'd love to see on hatchery systems would be the implementation of slowly allocating funds towards habitat restoration and eyed egg plants. I'm not necessarily saying to cut hatchery production really, but it would be cool to just slowly try to transfer over to different methods to see if they works. If eyed egg plants work, you eliminate the hatchery influence, and could possibly use it to help on smaller systems (or highly impacted systems) where hatcheries aren't practical? Maybe plant eyed eggs from 20% of the brood captured to see if we see and upswing in "wild" numbers.