Nobody cared about any of the MCU phase 1 heroes other than the hulk before the MCU. That was kind of the point they were at, they'd sold off the film rights to everyone actually worth something (Spiderman, X-Men, hulk) in order to keep afloat, and were working with the dregs. It's insane it worked as well as it did despite that.
They might have known who they were, but I don't know if they neccessarily cared. Captain America could have easily been a joke character that nobody took seriously, see;
And yet they were able to pull off a resonant scene above.
True.
Plus I just remembered they're gonna have all the X-Men to use too.