Yes, Pitbull still should have followed through with the challenge. People should always follow through with what they are doing or what they say they are going to do, no matter what. There are only a few exceptions where people should not follow through, but Pitbull was probably not one of them.
Regardless of the outcome of the election, he made a promise and he should have kept it. It is the right thing to honor the promise. It will also be a great thing for the people who live in that small town in Alaska. Above all, it is great publicity for Pitbull.
In today's world, honoring your words is paramount. So many things can get misconstrued due to the ever changing information, especially with the presence of social media and how fast information is spread globally. Pitbull in the past, has said that it is true to be good to your word and in this case, he should be a good sport and accept the challenge that he was involved with.
I don't blame Pitbull for not following through with the challenge to kiss a pit bull. These dogs can be very dangerous, and you definitely wouldn't find me kissing one! Most times, I don't think these types of stunts raise awareness at all---they are just for publicity on social media.