Not a standard LEAF thing. And 240V portable EVSE's are all over the map, they can be 6-20 or 6-30 or 14-50.
A LEAF owner (of which I'm one) would have had to have the forethought of not getting a permanent, or 6-20, or 6-30 EVSE initially, otherwise they won't just have a 14-50 EVSE lying around. I'd be shocked if even 5% of current LEAF owners is currently able to use a 14-50 without having to buy new equipment, or knowing they'd have to buy new equipment.
And Nissan dealers don't push or advise 14-50 in any way. I doubt they even know what it is. The dealer I bought the Leaf from last month didn't even know what J1772 or Chademo was - Nissan uses different terms for these. ('Charger' or 'Charging Dock', and 'Fast Charger' or 'DC Charger').
If a innkeeper really wants to support multiple vehicles, he needs to have a J1772 outlet. Not a 14-50.