Just came here to post this photo of the same thing, from the other side. So far I've seen several non-transit vehicles driving in the red area (including the truck seen in my photo).The City have now broken out their red paint supply to tell motorists that the block (or most of it) between Lower Sherbourne and Princess is for buses only! Will it work? We shall see!
Another vehicle coming south on Princess was halfway through a right turn before realizing their mistake and doing a weird u-turn in the middle of the intersection that was pretty... dangerous.
Whether people will follow the rules after an adjustment period or just totally ignore the signage (like on the King Street Transit Priority Corridor) remains to be seen. I know where'd I'd put my money if I was betting.