Tape in the U.S. was brand new but had been adopted immediately by all the majors, so "roll tape" is not an anachronism. But the release vehicle was still 78's only, so the lathe footage you see is cutting the master for disc duplication. That's where the editing is misleading, telescoping the time between session and release.
However it was a real session at the RCA studios for a real recording. I don't believe the mic, console, or room configuration was faked for what is basically a glorified newsreel.
Cheers,
3rd&4thT