The liberal claim is that we need to fix zoning that makes supply expensive instead of goodwill regulations that can't work long term because they don't address the fundamental root supply problem.

If developers build expensive housing beyond demand they can't fill as intended, driving prices down, why should this not be better than nothing? Even if it's less lucrative for them than expected, it should be net positive for renters...

I have no idea what the Liberals claim, but I wouldn't be surprised if this had little effect on the lowest rents.