Exactly correct. It is has to do with rules of the country where you are disembarking. And Btw nothing to do with the e ticket you need to leave.Covid test requirements when flying out of the DR have zero to do with the Dominican airport and everything to do with the country to which you are flying.
The USA requires a negative Antigen test, for example.
(Within 90 days we will know without the shadow of a doubt where CV19 came from. LOL I read it in the news.)
As of last week the test was needed to fly into JFK.