The end result is a lot more apartment buildings would be built in the city fairly quickly, dedicated transit bus lanes would be developed fairly quickly again and a lot more people would move in and a bunch of grumpy old people will complain impotently that their city is changing, but will not move away because the old don't like to change anyway. A bunch of other old landowners will cash in for above market rates and retire to florida to get away from the cold fog, stressful driving and high taxes.

So on net, a few will move away, the vast majority will shrug as usual and SF will have a lot more people in it.