As for waiting to see what Strata do with windows upgrade, I probably won’t wait as I’ve seen the proposed upgrades and they will have the same lack of sound-blocking qualities as the windows already in place. And it could be years anyway before that upgrade happens anyway.
At the risk of being accused of promoting one of our sponsors, have a look at the post from Gary from Windowline. A secondary window inside your existing one might be the solution you are looking for, it shoud be less expensive than a fully double-glazed sound-reducing window and it will not require a by-law.