I am struggling to understand why an MPL holder should have any more difficulty than an ATPL holder when it comes to ATC matters.
I have seen an experienced CPL/IR holder look at me with a pleading face when he failed to understand one single word of the ATC clearance flung at him by the female controller who was shouting at him via a tin bucket and a terrible old radio at the old Athens airport.
I have seen an experienced captain struggling to understand the old inbound ATIS at Istanbul and I have lost count of the number of pilots who found it difficult to cope on their first visit to JFK.
I can't see what any of this has to do with an MPL licence.
Incidentally, when I was driving Belfasts at Brize Norton many moons ago, we used to be made to listen to ATC broadcasts that had been recorded live in the USA, Hong Kong etc etc in the hope that we might just be able to partially "tune" our ears before we set sail.