I don't think Long Haul is in Luton's business plan, as you say this adds extra complexity catering for Business & First pax.
What it would like is a handful of 321XLRs and 787s for the leisure punter who will put up with Y class for a 7/8 hour flight if the price is right.
Many good reports about Wizzair Amman flights, Ok it is usually late but the price is a steal compared with MEA or BA. Repeat a bit further distance and it is a new market no-one else can touch. Imagine Dubai or Doha for £89!