I would be shocked if the July 1 openings on the other hatchery rivers weren't announced in advance. Well, mildly surprised.
The issue at hand here was that there are freshwater salmon regulations that pre-date any of the current DFO managers. Some of this regs in recent years have been changed where they made zero sense at all (e.g. an August non-retention on Chehalis Chinook was removed, Qualicum River Chinook retention didn't open until Oct 31, etc). Significant work was started last summer to try to streamline sport regs and make them consistent around Georgia Strait. For example, the Lower Fraser tribs had (until this year) always been open unless closed, whereas the East coast Vancouver Island rivers (Campbell/Quinsam, Puntledge, Qualicum) were closed unless decided to open in-season, as well as a patchwork of strange regs. The intention from the fishery managers last year was to get them all straightened for this year, but it seems the execution left a little to be desired.
The key point that was made to the fishery managers was that the heavily enhanced rivers are intended to support sport opportunities and harvest and should not require an in-season assessment of abundance. Open them up for the enhanced species, and if something catastrophic and unforeseen were to happen then a closure could be made in-season.
This is a good opportunity this year to provide input on these regs, as I still think there are some that don't make much sense. The previous fishery manager in the Lower Mainland (retired now) was very receptive to these types of changes, I'm not sure how things are now.