why are you so hung up on whether it's new or not, bigbird? the term is new, created by Gill Rapley, whose paper i presume you have read as you've previously said it would be useful for your studies.
the concept, philosophy, what-have-you of blw is still being tested, no-one really knows what the benifits or otherwise will be, they can only make educated predictions based on knowledge of human behaviour.
everythign you say about development is correct, but you surely must acknowledge that HVs are still telling people to start with purees, operating on the assumption that it takes a couple of months of spoonfeeding before finger foods, rather than that babies are ready at 6 months ish? that this is not the case is revolutionary knowledge to some.
i never did purees, but it would certainly be more effort for me to spoon feed purees than to hand her some of my dinner. and plenty of people have done both and found blw to be less fuss, so as it happens i take their word for it.
i also know that i have never been able to give my dd an ounce more of milk than she wanted, so i assume that the same would go for puree. however i have definitely seen my friends spoon-feed their children beyond a point when they appeared happy, employing all sorts of distraction techniques in order to get them to finish the serving of food. so have other people on these boards... harpsichordcarrier has a particularly grim story of a child she met.
i just don't understand why it's so important for you to prove that it's not new. my mum spoonfed me, and my brother and sister got more finger food, then my youngest sister was essentially blw'ed because we were around to share our food and it was less hassle for my mum. that was in the 70s. there's nothing new under the sun, and no-one's saying that there is.