Something would only happen to the losers who inherited the first generation of HDB flats. They are our version of sinkie losers, pretty much like the American version of the losers who stay in their parent's basement instead of moving out when they reach adulthood.
When my kids grow up and get married, I expect them to fuck off from my bungalow and start their own life in their BTO flats. If they continue to succeed in their professional lives, they can sell off the BTO and move up a more luxurious home. Otherwise, be content to stay in their BTO until they pass on. And the cycle repeats itself for their own kids.
Even for singleton losers, most of them I know aspire to buy their own HDB apartments once they are above 35 years old. They too don't wish to remain forever with their parents unless they are underachievers. In most societies, voters don't have much patience for underachievers. We expect voting adults to be able to take care of themselves.