It is nothing new. Back in the late 1980s or early 1990s I caught the Dan Air shuttle from Manchester to Gatwick, plane said Dan Air on the outside but the signs in the cabin and the booklets etc in the seat back where in no language I could recognise.
Absolutely its nothing new. I once flew AGP-LTN on a Futura 737 on behalf of Monarch. Flight and cabin crew all Spanish; in-flight meals definitely not English (whatever it was!). I think the crew weren't totally familiar with LTN as we went pretty much the full length rather than the typical Taxiway Charlie turnoff (landing 26), having to make a 360 degree turn at the end of 08. Never had to do that before.