Yes, although blocking or accessing an account abroad by Brazilian authorities can take months.
Accounts abroad do not participate in the Brazilian systems of judicial attachment or administrative controls, such as the Bacen Jud managed by the Central Bank of Brazil and the Judiciary.
In this sense, when judges or other Brazilian authorities intend to block or access assets from an account abroad, these authorities must send a notice to the authorities of the country where the accounts and assets are located.
For example, a Brazilian judge would need to send an official notice to a judge in the US in case the national authority requests the blocking of an account in that country.
This procedure takes time (generally weeks), and judicial appeals from that jurisdiction regarding the court order issued in Brazil can be appealed abroad.
Important: Brazil is currently a country with solid institutions and laws in line with international standards.
However, if this situation changes in the future, there is an advantage in having an account abroad. This advantage is protection against abuse by local authorities, given that assets abroad are also subject to some appreciation by the authority where the assets and accounts are located.