There's no magic here since eventhough how promising bitcoin in terms of profitability for holding it for so many years still we have a huge risk that we might don't get the target price we set for future and sometimes a huge dumps will came and that can affect their economy but I'm sure he know on what he is doing since for sure he have experience advisers on his side and have a proper planning on what actions they need to do once the market collapsed on certain times.
I don't think they're just buying it for the sake of holding it; I believe it's to help their economy cycle since they legalized bitcoin, and I believe they'll offer it as a payment method just to get people to try it, or they're planning something big. Though, in terms of holding it, there is still a lot of risk because we don't know what will happen, but we should be prepared for losses as well as wins because there are times when it is dump. However, risking is the best option because you will know whether or not you will win.
However, if this big decision will possibly work in the near future, then it will also create a big progress in the country that will also benefit all its citizens. Although this is something to be fear of because of its win-lose scenario, but knowing bitcoin it will always end up into a a huge success.