Public housing - originally design for those people in "needs" not "wants" so if some people already over the criteria, they should move out and pass back the vacacy to others whose in needs....
I dont see the reasons why it will make the properties market become hotter..
Actually the new properties are sold very slowly now, as the price is really too high. The developers just are not willing to reduce the price but rather sell the properties little by little. Maybe the no. of mortgage years of those unsold flats should be reduced accordingly, then the property price of those unsold flats should drop.