The InFlight magazine mentions that in relation to Duty Free, they may not carry a particular item onboard and that the crew can offer alternatives, and so I was curious for example, on a flight from Morocco->London (or indeed London->Paris post-Brexit) how many 1L bottles of Duty Free alcoholic drinks and/or 200 pack of cigarettes they'd typically carry for an extraEU flight?
Not sure even crew would be au fait with the details.
Likely Retail Sales operation at Ryanair plan the range that will be available across the network. This done on basis of historical sales plus a look at passengers / events occuring and a view on route.
So a flight to Paris for weekend of 6 nations likely have lots of beer on board where as flight on way to Grannys convention then lots of Gin.............. etc.