<most sites indicate that "w00t" ("woot", "whoot") most likely comes from the song "Whoot, There It Is."
"Most sites"? Not the ones I looked at. I did find a couple, though. If you would like to publish an authoritative summary of your research, however, perhaps I could be swayed.
I saw the word in fantasy comics all the time when I was a kid in the 60s and 70s. You know, the sort of genre were folks would run around saying things like "s'blood" and "by the rood" and of course "woot!".
Furthermore, I heard the word used by D&D players back in the 70s, you know, the guys who got together and rolled all those funny looking dice from time to time before computers could do much more than play the games that led up to "Zork".
I suspect that the indicators on the sites you mention were about 11 or so when "Whoot! there it is" came out (closely followed, of course, by the considerably better known "Whoomp! there it is"--probably the one they actually heard, given the subject matter of the former and the activity of Tipper Gore et al) back in 1993. And I'm sure you'll agree that we have a tendency to assign a more universal significance to the music we listened to as adolescents than it really deserves.
So, I disagree with your assertion that this is a majority opinion, and also that it is a correct opinion, which is easy to do since I saw it around long before the song came out. In any case, you may wish to have a look at
if you haven't already. That's the version that most people are familiar with, and much sanitized over the original by 95 South. I suspect that those who realize that the "whoomp" version is a bit of a ripoff of the "whoot" version are few and far between, e. g. I doubt that Dennis Archer was using the "whoot" version at his mayoral victory party in Detroit, given the lyrics. (On the other hand, in an incident that made the news on a slow week, I suspect that a number of young men at the city swimming pool showing loud appreciation for a young woman's derrière most likely were.) My point being that this strikes me as "urban science", which is a subset of urban legend. (I had to explain the term because I just made it up. If this becomes a mainstream term, I'll be interested when I turn 100 to see all the examples of it used to determine where THIS term came from.)
Bob