This may be true, but FWIW, the first time I heard the term it was introduced to me with a similar backronym. And not as some "isn't this awful classism" disclaimer, but as a gleeful denigration of the people it referred to. That there is an older etymology does not necessarily mean Jones invented the backronym.
>Actually I said chav because that group of loud, ridiculously dressed arseholes over there is starting to kick off
While I too have used the term, and feel like I was doing objection to genuinely unpleasant people, I remain suspicious of this argument, because it sounds a lot like "I don't mind black people, I just don't like black culture". A lot of what gets read as obnoxious is just cultural differences, and this is especially true of judgements like "ridiculously dressed".