They're leased ACMI.
As long as it doesn't fly into European airspace with a Garuda flight number, it'll get in. As long as it's maintained to the applicable standard of Futura, it can get in. In fact, there's no ban on Indonesian aircrew from flying into European airspace. The ban applies to airlines under the regulatory oversight of the Indonesian DGAC.
So the 2 738s from Futura are piloted by Futura crew, engineering provided by Futura and/or Garuda to Futura standards, Garuda cabin crew, dispatchers, loadmasters, ground handling,etc.
In fact, during Hajj, Garuda operated A330s and 767s from MYT and TUI... it remained on the European registry, operated and maintained by the original carrier, and when it left Indonesia to enter European airspace, it did not use a Garuda flight number. Those planes are under ACMI leases through the Hajj period, with cabin crew from Garuda, engineering from the original carrier, with 3rd party (Indonesian) dispatchers (using standard plans of the original carrier), load masters and ground handling...
The short answer to your question is: EU won't look at these planes with disgust when they return to Europe.