This has resulted in questions about where sovereignty lies and tweets with the hash tag #ThisIsACoup
While it is not a coup it does show that joining a currency union does have an impact on a nations sovereignty and underlines why a country needs it's own currency. It demonstrates the wisdom of the UK in keeping the pound, and it's good to note it appears to have stopped the argument about joining.
The other thing to note is the reaction that Greece might leave the euro generated. It clearly showed that there are those in EU who believe as an article of faith that there can be no moves away from European Integration. In February 2015 Jean-Claude Junker saidsaid (in French) "Il ne peut y avoir de choix démocratique contre les traités européens" or in English "There can be no democratic choice against the European treaties" By putting their articles of faith of European integration above democratic choices and economic facts they are just like flat earthers or young earth creationists who not only put their faith above recognised facts but reject generally accepted scientific fact in favour of pseudoscience. We listen to the pseudoscience of the European federalists at our peril.