there’s nothing here that leads me to believe that this gives the owner the right to replace noise insulating carpet in the living area with tiles. Am I wrong?
Your strata manager is being a bit cute. There’s nothing there to tell them specifically to lay down rugs but there is plenty implied in the by-law that requires them to insulate the floor properly. Simple question – why should they be allowed to enhance the value of their property to the detriment of yours?
Ask the strata manager and committee which they would prefer – either enforce the by-laws or be dragged through NCAT, then have to enforce the by-laws, then have to explain to all the other owners why they have to pay your legal bills as well as their own just because they were too lazy or misinformed to do the right thing when they had the chance.
And start making a diary not of every noise from upstairs, record the noise on your phone and get neighbours to listen so they can back you up if need be.
This will cost the selfish B upstairs a lot to fix but that’s not your problem. You only have to know they will put up a fight and be ready for it.
Oh, and ask your strata manager if they have read the SCA’s code of conduct. If they have, why are they ignoring it?