Not sure it's a good idea to keep values longterm in centralized stablecoins. I really think the centralized ones shouldnt exist in isolation as long people's money is involved.
Definitely you should not be depending on the centralized coins for long-term holding. Because government may seize these corporate at any time like how they did with Liberty Reserve for the reason of money laundering. Yes, there are big possibilities for stablecoins to be used for money laundering because it is easy to move and there will be no to less risk of losing value due to fluctuations.