Low-cost and social housing tend to be sold to organisations rather than individuals, whether it’s housing associations, charities or local governments, as they are in the best position to regulate the access to the most deserving or appropriate tenants.
Since they are the owners, they would be paying the levies, as would other landlords, so they are less likely to default on levies than owner occupiers or private landlords.
Since rents are rocketing and rental availability is very low, private landlords are protected to some extent from rising interest rates.
Thus the most vulnerable group to levies stress is probably owner occupiers who bought when prices were high and interest rates were low, stretching their resources to the max when the financial winds changed direction.
I don’t think there is any model where low-cost apartments are sold to individual owners (please correct me if I am wrong) although there may well be some buyers who benefitted from first-home grants who are now feeling the pinch.