One conclusion that seems to be almost implied by the story's ending is that Rainsford will become just like Zaroff, taking his place and becoming like him. After all, he has already become the human hunter... We can hope that he does not lose his sense of right and wrong, but there is some reason to wonder if he has already lost it in being forced into a life-or-death struggle with Zaroff.
It is possible that Rainsford might decide to give up hunting altogether, now that he knows what it feels like to be hunted. Something like this occurred in the movie The Deer Hunter. The main character played by Robert DeNiro found that he didn't want to shoot the magnificent deer even though it would be the best prize and the best shot he had ever had. He had been a hunted animal himself in Vietnam, and he knew how it felt to be in danger of losing his life. A lot of us do not have to go through the experience of being hunted animals in order to learn to feel sympathy for animals who are hunted for sport. We might kill an animals for food in a distressed situation, but we wouldn't kill an animal just for fun. There are a lot of other ways to have fun.
I think there are a lot of responses to this question as it is asking for your opinion.
In my opinion, considering Rainsford's anxiety over the three days running through the woods understanding what it is like to be the game in a hunting expedition, I would hope Rainsford would lose his desire to hunt. He did talk about at the beginning his love for a good hunt. No longer would I think he would find enjoyment in tormenting an animal by chasing it, trapping it and finally killing it.
Another idea would be to look at this good night sleep he got at the end of the story. Perhaps Rainsford will keep his post there on the island and enjoy the Caribbean island lifestyle - hopefully without resorting to murder as entertainment.