It is entirely feasible that Cabanas have more than one use.
I suspect that now that the government is focussing in on prostitution, that just one or two examples of Cabana use for prostitutes out of the thousands of privacy/concubine uses will be enough for that Cabana to be shut down and forfeited due to promoting prostitution (in case anyone says that prostitution is not illegal in and of itself, while promotion of prostitution is illegal).
The girls are going to have to get their own places and be entirely on their own as private contractors.
Cabanas have multiple uses.
Many in the DR live in small, multi-generational houses where privacy is limited.
I know couples with kids and parents living with them who use cabanas to cap off a "date night."
I have nephews who live in smaller apartments who use those large, 2-level cabanas for parties, bringing a sound system, drink and food with bunch of their friends converging for a few hours of partying.
We use cabanas when we travel to Santo Domingo. The convenience of just pulling in and not having to go through the front desk hassle is so nice! We have a "Cabana Bag" ready at all times with better sheets, a blanket, pillows, coffee maker, and even our own shower head (they are usually missing in a cabana). RD$1200 for 9 hours overnight with a simple breakfast just can't be beat. We bring an extra fold-out table, water and chargers and we're all set for the night. We probably stay in a cabana 35 nights a year, and have even discussed future longer-term rentals with the owner.
Certainly cabanas are used for affairs and prostitution, no doubt. But to say that is their only use is just flat incorrect.
We spoke with the owner---it one of the nice cabanas on the Malecon around Luperon---and he claims almost half of his clients are salesman, short-stay overnighters like us or family/couples, and stays especially busy when one of the local societies, like the Spanish or Lebanese, have a big event.