Adriaticum, you are bang on when you say low water is bad for fish too. The stress level of all these trapped fish, pounded all day (and night in a few places I understand) must be off the charts. And stress is known to impair (or totally stop) spawning success.
Unfortunately, it's possible the coming rain is 2 weeks too late. Water levels this low means off channel spawning areas are totally dried up, too low or unaccessible for spawning pinks, especially in the lower river. Have a look at Peach Channel, from Peach Road down. That means nearly all the pinks have spawned or are spawning in the mainstem river .... with virtually no back up spawning in side channels. A good November flood could wipe out what was probably the strongest pink run on the Chilliwack in a long, long time.
Saving graces are the off channel spawning areas in the upper river (Centennial, Yukalup, etc), Sweltzer Creek, and the hope there are still a few pinks to come that will access these soon to fill to be wet again channels.