I don't think the bank might freeze Tether's account. Freezing will occur if there is a report of fraud committed by Tether. Because Tether is an official company, so they have a strong legal foundation. And the central bank can also take legal steps if something happens scams.
True, the Central Bank will not take silly actions if an accusation has not been proven right, because they have a legal basis when following up on something that they suspect, and so far I personally have never found anything scam with the Tether company.