Who is doing the blocking (if they were really blocked)? Did the owner/owners commit any crime? And was the crime clearly stated for the public to see? Are the stablecoins with such block feature decentralized or centralized? If decentralized, is the blocking done via network consensus? No true decentralized stablecoin/crypto should be blockable without proper, transparent and community consensus. So, I would avoid any so called decentralized stablecoin that can be blocked without proper consensus. Decentralized coins should be censorship resistant and transparent. The only coins that could be frozen/blocked are those that have been used for serious crimes or owned by serious proven criminals.
Stable coins are always centralised. Blocking is done by by owner/developer. This also beside it is centralised also makes stable coins not permisionless. Since you need permission from owner/developler if you can or not use it
Stable coins are not cryptocurrencies!!!!