Well, we just went over to the spot on the trail near where the bikes were found. There is police tape blocking the trail from where the inside fence starts, so we couldn't get down to the narrowest part. I took some pics, nothing much to see though, except how the trail narrows there and goes into a tight, tunnel-like spot.
We also checked out the pump house. There has clearly been lots of activity around this spot, and the driveway is more visible than I remember. From the building (which is no bigger than a small garage), we could see the lake through the trees. We could barely see the trail as well. There is no spot in the driveway that we could not see/be seen from Arbutus, and the police station is about one block away as well.
We went to the park, which is across the lake from where the bikes were found, and could see, across the lake, a vehicle parked near the rock jetty, and more police tape blocking the trail there. There were police- uniformed and otherwise - at the park, some people who seemed to be maintaining a vigil (lawnchairs, cooler, etc) seated near the lake's edge, reporters and news trucks, and other onlookers.
We just got home to see they are draining the lake. The scenario of someone taking them while parked in that pump-house driveway seems much less likely having looked closer - the undergrowth is thick but the woods really aren't, so you wouldn't have the sense of being out of sight at that spot.
I don't like seeing some reports that the girls went missing after riding to the lake, since nobody knows that they actually rode to the lake. But, given Occam's Razor, I suppose finding the bikes there, etc, means it is the most-likely scenario.
Draining the lake is a wise idea. They actually just drained it about two years ago, after the major floods in the area essentially wiped out any decent fishing, etc, and it had taken a year or so to slowly re-fill. We saw the police in our neighbor's backyard when we were at the park, so we came home but have not seen any LE since.
Part of me is hoping they find something in the lake, part of me is hoping they do not.