No, it was almost certainly a typo. There is no condition under which "waste majority" makes sense, but the poster was talking about waste, and the two words share 3 letters in common, so an easy mistake to make when typing quickly.
But for anyone who's not 100% comfortable with English, "the vast majority" is not simply a case of a descriptive adjective modifying the noun "majority," but it's actually a common phrase. People don't say "the big majority" or "the large majority," it's specifically "the vast majority."
If you wanted to use a different adjective, you could say "a large majority," and that would mean something like "most but not all and the 'but not all' is kind of significant" where as "the vast majority" means "nearly all of them, and the 'not all' is insignificant."
