Funny thing is that Cuba already has its own "airbnb" called "casa particulares", it's definitely a great way to travel! :)
The problem I see in the short term: mobile internet for travellers in Cuba is rare / nonexistent and internet access for locals seems not ubiquitous. Probably both will change soon now that embargoes are lifted.
Interestingly in Cuba it is illegal to provide free sleeping accommodations. CouchSurfing and the like are wholly illegal there so casa particulares are the only option for homestay.
If anything, this will help AirBnB adoption since the concept of renting out a spare room is already widely known.
No, it means something like "independent household". But functionally, yes, they are "bread & (maybe) breakfast".