No evidence of UFO/Alien contact will be made by anyone!
No controlled human organization on this planet will ever release evidence of UFO/Alien contact to any of us. It is not In the best interests of those organizations, that have had contact to disclose fact to the planet.
It would require AN ACT of GOD, to bring the proof public.
If ETs were altruistic, they would bypass all the criminal governments and directly contact the people. And if they were not altruistic, they would still not waste time contacting the governments and would just take by force whatever they wanted.
So, since neither has happened, I argue that ETs have not visited Earth as yet.