Yes, even if you are added as a co-owner of your parents’ HDB flat with no monetary consideration, you are still subject to a Minimum Occupation Period (MOP) of five years. The MOP is a regulatory requirement that applies to all HDB flat owners, regardless of whether they provided monetary consideration or were simply added to the ownership. This means you must wait five years from the date you became a co-owner before you are allowed to purchase any private residential property such as a condominium. It does not matter if you were previously just an occupier; the MOP starts from when you officially become a co-owner.
It's great to assist you through EdgeProp Buddy. It's prudent to get professional real estate advice on such topics.