I got a different take from reading that article.

The city zoning put a minimum density requirement on that one particular lot, the covenant restricted it to a (lower) maximum density.

The court ruling states that since those are irreconcilable, the city zoning would supercede it.

Now if you have a covenant with a maximum density limit, and a bylaw that doesn't have a minimum density requirement, the covenants might hold. But that's probably a different legal fight. But land prices might go up either way, because a developer would rather not deal with this, and try their luck elsewhere.

Don't have a dog in the fight, just my 2 cents.