This bit is particularly questionable. It's unproveable -- if a text was only transmitted orally, there's no way to compare its modern form to an older version -- and it's probably wrong. The short-range memorization techniques described in the article don't guard against larger-scale errors in memorization, like omitting a "chapter" of a text, nor do they prevent single-word changes, like a student mishearing a word for another similar-sounding word.
What this meant was that language stopped evolving since last 2400 years ago. You can create new words but there are precise rules for it. All this means there is no scope for "dialects", words meanings changing with geography etc. Different vedic chants separated by thousands of miles and 1000 years in time are exactly the same and perfectly understandable in any part of the country for anyone who has studied Sanskrit.
This makes Vedic chants unlike anything English, Latin or Arabic has to offer.
As for the vedas, specifically Rigveda (which is the only one I can comment on with some expertise) we have what we can call different recensions of the text. These texts, independently transmitted, differ very little from each other. This fact alone strongly indicate that even while they've been orally transmitted for many generations, they are more or less uncorrupted by the act of transmission.
Much more could be written on this subject (and has been). However, english isn't my native language, it is late and this comment could go on and on…short story is: memorization and oral transmission seems to work!
This is important. This constraint alone helps oral traditions a great deal.
Imagine you had to pass down a Java program (through oral tradition) to sort numbers and you had a Java Language Specification that remains unchanged. Now compare that to say English language where and you write an essay on sorting numbers. If both things are passed down orally over few dozen generations which one is likely to keep its form ?
https://hinduism.stackexchange.com/questions/9517/procedures...
"Divisional protection" appears to simply be stating that the Vedas are divided into sections. This doesn't provide any form of error correction; it's simply a means of organization.
"Meter protection" states that the Vedas consist of metrical verse. This provides a limited level of protection against certain types of errors (like inserted or deleted words), but not against larger changes.
"Swara protection" and "Mudra protection" state that the chants are tonal, and that those tones are associated with particular gestures. I'm not sure what protection this is meant to provide.
"Patha protection" is a restatement of the same memorization technique described in the OP.
A system of chanting for memory has been used since pre-history across many cultures. See for example Greek epic poetry, Hebrew Scripture, Arabic Koran, Anglo-Saxon Beowulf, Viking sagas.
In ptr-literate societies, bards were able to memorize huge amounts of information and recite to their listeners. Much of the poetry with its rhyme/meter/repetition was written that way to aid in memorization.
That sort of memorization got a lot less as literacy grew and people could just read stuff for themselves, but it was pretty widespread and certainly not something unique to the Vedic tradition.