Air France, KLM and Virgin Atlantic recently started an extended codeshare. You can even book a full itinerary on VS metal with AF/KL. What’s great about this is that on many dates and routes I priced between the US and London, booking on AF/KL can be a few hundred $ cheaper! (Google flights will give you the cheapest booking option). What’s even better is that the flights that are booked on AF/KL as economy light without assigned seats or checked bags, are coming up on the Virgin system as classic economy with seats and checked bags! This is definitely a glitch, so enjoy it while it lasts...😄