"WHY do this when there are countless unedited versions to check against?"

We have countless versions we can examine, to compare and contrast and study. But decades from now, when history is jelling into the "final" version, it will be the edited, approved transcripts which will survive, not the earlier drafts.

Future historians will lose the context, they will only have the "approved" version. And they won't have any reason to question it like we do. Future scholars may not be as familiar with the controversy and uncertainty that exists today, so they won't be as motivated to reconstruct the moment like we can. The canonical text will be established.

Historians like to think we need context and perspective to properly evaluate historical data, that historical truth eventually emerges from past data as we contrast and compare it with the events leading up to it, and the research and analysis subsequent to it.

I don't believe that. The longer we wait, the weaker the signal gets. Bits get dropped from the data stream. Some accidentally, some deliberately. I'm old enough now to realize some events I actually participated in aren't logged in the official record the way I remember them going down...

You're absolutely right, its what fascists do.