The Vancouver STARS (standard arrivals routes) were recently changed; expanded really. As a result, on some days transpacific (and S transborder) arrivals are indeed descending to 3000 while making what is essentially a left-hand circuit to 26R (on other days its the more usual right-hand circuit); putting them low over the areas cited as being affected.

Yes it is "new", ie. happened after those residents most likely moved in.