Is the Fermi paradox gate keeper disinformation?

The conversation in which Enrico Fermi asks his colleagues if the universe is so large and old why aren’t we seeing evidence of aliens. That conversation happened between fermi , Edward teller and Herbert York and a couple others. This was in 1950 which was years after Roswell and several other well known alleged crash recoveries. Edward teller is considered a likely architect of the ufo reverse engineering program and anti gravity tech. All of the people present would have had clearance for atomic secrets.

So is the “fermi paradox “ a fake? Did these guys already know about retrieved non human bodies and craft?