They said in the presentation that this was an unplanned issue that EPCOR had to fix, and their priority is keeping 107 Ave at two lanes in each direction. Regarding other mitigations: They chose a very simple bridge design for Wellington, and are starting work in the winter, so that the schedule can be accelerated (but it has to happen because they've had to do an increasing number of adjustments to the temporary scaffolding); they're also delaying the Wellington Bridge until the VLW acceleration work is done; they changed the scope of Dawson Bridge so that it doesn't need a full closure this year; and Jasper Ave will go down to one lane in each direction only during the construction season, during-which they'll complete the entire phase, so that come winter it's back up to two lanes in each direction.
Not saying they are or are not doing enough, but it does seem like they're making an effort to account for broader impacts.