Raises some interesting questions, ones applying to monks copying out old manuscripts, who are said to have made mistakes.
The early Church was very selective, the Book of Enoch was mostly excluded from Christian canons, and it is now regarded as scripture by only the Ethiopian Orthodox Tewahedo Church and the Eritrean Orthodox Tewahedo Church. The early folk collectors would have also have censored the more prurient verses, as they came from a time when even table legs were draped to preserve their modesty. It is difficult ti be certain what was original, what was deleted and what was modified. It is not a subject I have studied but even "sciences" such as archeology are not immune to having the narrative hijacked. It is a brave man that raises his head above the parapet and expounds a counter argument against his peers. In the early 20th century Wegener was ridiculed for proposing continental drift. In the 1960's the causative agent, namely plate tectonics, was pretty much taken as a given as soon as it was proposed.
Progress inevitably ends up a blind alley on occasions, before it stumbles along a more fruitful path.
What the early collectors say they did as opposed to what they actually did is a bit of a conundrum. There is also an argument that by collecting they sterilised the folk process, if you believe such a beast exists. I can believe mutation exists, it is the supposed scale I have a problem with.