I think it's fair to say the acoustics of every building are different which is one of the reasons it's unwise to create prescriptive by-laws that either don't sufficiently address the issues of noise or, alternatively, are so draconian that they could, feasibly, be challenged at the CTTT or in court.
The only real test is whether the occupants of one unit disturb the occupants of another unit because of their floor covering and the way they behave in the apartment.
One of the isses with hard flooring is that they reflect noise into the air (if you want to sse this at its worst, go to a busy cafe with concrete floors and low ceilings and try to have a conversation). Some of noise, obviously, will be transferred through walls, ceilings and pipes (which is why some buildings ban you from playing your radio in the bathroom – true!).
There is also a question of indirectly transmitted noise where, theoretically, vibrations from a floor can be transmitted via a wall to another wall above or below. And until someone does a study on the transmission of noise via the structure of a building, all of this will remain a mystery.
Plainly and simply, nothing absorbs noise like carpet but that shouldn't mean that we all have to re-rug our floors. However, we shouldn't expect our neighbours to put up with excessive noise because we want a trendier or easier to clean floor.
If I were putting together a by-law on flooring, it would say that you can put down whatever you like provided you sign a contract agreeing to rip it back up again if it proves to be a nuisance to other owners (by any reasonable measure).
Put the responsibility back on the renovater to either get it right first time or keep fixing it until it is right (with some guidance on what has been shown to be effective and warnings about how cheap flooring with inadequate insulation end up costing more when they have to be replaced).
For ground floor flats with vertical and lateral noise transmission, you might think about installing acoustic walls and ceilings which are often a lot cheaper than you'd think.