Closing Geylang will not mean the end of the vice trade. It will either go underground or spread all over the island. The new generation leaders will find the country in a worse position if they closed off Geylang.
Unless they want to shift the trade to Marina Bay along with those high end gambling dens. Then it will be another story.
I heard from sources that in the next few years, government will push and relocate all the vices to the outskirts of the island, example Tuas, Changi, etc... They will reuse the land of Geyland to build more flats, shopping centres, factories, etc... By that time, property prices in that area will go up...