I can see this being iffy, I’ll never be sure a car in that position has seen me and is waiting or pausing for some other reason and will turn when I arrive along side. I’ll also mention my dislike of when drivers pull alongside indicating then look annoyed or mouthy when I slow or signal because I’m not psychic and can’t tell if they’ve seen me/care about me. Be smoother to just edit behind as per HC rule 182 (current version)I think it is indeed saying "Don't left hook cyclists".
I had one on Wednesday night night on the way home, where the car driver did what this change says they should do - a pleasant surprise. I was in one of those fairly narrow painted "cycle lanes", a car comes past me, indicating left, with a junction a few yards away. I expected him to just turn, and was on the brakes ready, but he didn't. He paused and waited for me to pass.
AIUUI, that is what the new rule is saying he should do.