The straight up property tax (per property, no exceptions) will be added at some point. Municipalities can't make so much money by selling land anymore, and the central government doesn't kick back enough tax revenue. Not only that, but they have committed to eventually providing social services to migrants, like you know, schooling for their kids. That has to be paid for someway.
But they will definitely hold off for now, a property tax would cause huge devaluations in property prices inflated by the lack of one. But if we get a crash anyways, it will be easy just to add it at the bottom. The question is what is next, with transaction reaching a very low bottom to keep prices from falling, we seem to be in for a long bout of stagnation which will drag down the larger economy even more than if a crash would just happen and we could be over with it.