I'm not so sure something like this could happen... There is a feature where you can cut parts out of a video, but you can't add anything else in
I feel like the ability to basically change the content of a video could be used well, sure, but could also be used in a bad way.. Maybe to create hype around a video, get peoples support then swap it out for something either unsavoury, or something else they're trying to promote (or something similar, I'm not sure)
I think it wouldbe helpful for some people... but I've not heard anything about them adding a feature like that
YT desperately needs a way to edit videos post upload. Either that, or a way to REPLACE a video without losing its position. It takes a lot of work to get a video ranked up. We should not lose that ranking, just because we want to edit an error out, change some information, or add an update to it.
There is no doubt that people could use it wrongly, but that is the case with everything. If we were to eliminate things and knock good ideas based on whether people could abuse it, I suggest we do away with the YouTube and the whole internet completely, because it has an unimaginable capacity for abuse and uses for nefarious purposes. I am going to go out on a limb and suggest that you think eliminating YT and the internet is a bad idea, in spite of its enormous potential for abuse.
In life, it is unjust to punish everyone by taking away their rights and freedoms, just to attempt to prevent a few from using those freedoms for evil (which does not work anyway). If we go down that road, then we will eventually have to eliminate all personal freedom from everyone. No, the right way to go about things is to punish only those who use their freedoms to do wrong.