What you're basically saying is that every recording Guthrie did was live, so this must be wrong.
Lol.
I've never heard of a non-live recording...except maybe some performance art neo-modernist crap.
The point is that Guthrie performed differently in front of a crowd than he did on the radio, or in a studio, and there are NO RECORDINGS OF HIM PERFORMING IN FRONT OF A CROWD. Until this one.
That sounds unbelievable, but the man died of a debilitating illness, after being hospitalized for a decade, while he was still fairly young, in the 60's. Long before that time he was blacklisted for being a communist and few people would host him, let alone record him. You think fans were streaming to his 200 person venues in the 30's with closet-sized recording devices to get his live words onto tape?
I have this album, along with the Moses Asch recordings and the library of congress recordings, and I can tell you there is an appreciable difference that you will not find in any other recording. Yes, those were live. No, neither Moses Asch nor the LoC count as a "crowd." I guess his daughter must know more about the man through living with him and taking over his musical legacy than you do through hearsay and assumption. Stunning!