its the most logical translation into english language of the government-mandated action that closes bank depositor windows at the start... or during a bank run... prior to a major currency devaluation.

This is true at least in french, portuguese, and spanish.

I understand the problem that a "bank holiday" in the US is actually used to identify a federal holiday.

I don't think this expression has been used a lot in recent times (in anglo nations) since there hasn't been hyperinflation in US, UK...but there is a record of such expression :

https://en.wikipedia.org/wiki/History_of_the_United_States_(...

The expression "Bank Holiday" is actually really common in the UK - I would expect most brits to know it. We use it to refer to a public holiday in which the banks are closed, there are quite a few every year. It has very positive connotations here.

Bank Holiday is an American thing too. FDR declared one in response to bank runs in the Great Depression.