Greetings from Ireland, the new legislation may be impactive but it doesnt apply to all Airbnb hosts and all areas, also, its enforcement will be a problem due to lack of resources in the relevant local government authorities, so many Airbnb hosts will proceed to host as normal, as mentioned - many Airbnb hosts don't fall into the category being restricted anyway.
As an Airbnb host myself (my property in Dingle isn't affected by the new 2019 legislation) and an occasional Airbnb customer, I understand any booking you make withAirbnb is covered/guaranteed by Airbnb in the event the host may have to cancel your reservation. But you should confirm this with their customer service Dept.
Enjoy your travels in my beloved homeland :)
Rick Steves Tour-Guide
Dingle, Derry and Dublin