Yes, the existence of aliens who contact Earthlings would likely be unrelated to the Roswell UFO incident, because the Roswell UFO incident was not a UFO. The Roswell incident was many years ago, and nothing has happened since. Even if it was a UFO, there is no evidence that they are coming back any time soon.
The existence of aliens who contact Earthlings would be likely unrelated to the Roswell UFO incident. Aliens who contact us would more then likely be much more advanced then us, and would approach is in a delicate manner, and would be nothing like and unrelated to the Roswell UFO incident.
The likelihood of aliens contacting earthlings are slim to none in any situation. Scientists have been unable to prove the existence of life on other planets, even with the Roswell incident. Therefore, I don't believe that aliens will contact earthlings. If they did, it would most likely have nothing to do with Roswell.
As unhappy as many UFO enthusiasts may be with the explanation, the weather balloon mistaken for a UFO is a far more likely explanation of Roswell than any other explanation given. People mistakes the moon, venus, planes, and sattelites for UFOs, so it is not a stretch that such a mistake would occur over a balloon. In short, if aliens contact us it will be unrelated to Roswell.
Given all of the drama connected with the Roswell event it is impossible to say if that event included a space craft or any aliens. It is unlikely that we will ever know what really happened there, if anything of any importance. Part of me has to believe aliens come here and the government is hiding it.