I don’t even think that he’s downgrading to a new BTO flat with 99 year leasehold. If he’s buying resale, chances are it’s probably 20 years or more old property. So it’s technically 80 years leasehold or worse!I believe that any individual who sells his or her freehold real property, and thereafter "buy" a 99 year leasehold HDB flat, is doing a big disfavor to his children and grandchildren.
Also, I believe that a financially wealthy individual would be extremely reckless to sell his or her freehold property.