There's a scenario here that everyone seems to be missing out on.
This exact same thing (creel finding high release rate of hatchery fish due to anglers not wanting to stop fishing) happened on the cowichan. They cut that program. When a program isn't being used as intended, there's no need for it (especially with the concern surrounding hatchery genetics mingling with wild). Personally, I'd rather see a rule change than losing it outright.
Based on those creel results on the chilliwack/ Vedder since 2018, my feeling is that this is an effort to convince anglers to kill some hatchery fish (prove utilization of the program/ Stop hatchery steelhead from spawning). If the creel continues to find that hatchery steelhead are being released, even after increasing to 2/ day, it probably wouldn't be a good thing based on history. If everyone petitions to keep it at 1/ day, and creel continues to find high proportions of hatchery being released, the results would also probably not be good.
At the end of the day, a 2/ day limit would definitely increase retention. I don't really care for steelhead, and tend to release all my hatchery fish, especially if it's 1/ day. On 2/ day rivers, I often find myself killing my first one to hand as a gift for a friend, and continue fishing. Sometimes if it's near the end of the day I'll even kill my 2nd. With the huge number of people starting to drift the C/V now, there's no doubt that people will retain their first and then fish the rest of the day. Right now they'd definitely release the first.