Here's a data point for those with a 074 stock: I have this itinerary around end of year to LAX, via AMS outbound and via CDG inbound. Had a long chat with the KLM platinum service line to see if it could be moved to a date after summer next year, but they said it could not be moved to more than 30 days in the future without repricing, even with I class availability.
Moving to 006 stock is not something that seems possible without any DL flights in there...
Not sure what I'll do, but open to any strategic tips!