to be fair I think this is just a moving area of research and it isn't clear but, mother's might prefer it if all the research into a particular subject unequivically said the same thing but alas that isn't always the case, and sometimes you have to make the best judgement you can with the information available.
For what it is worth, Harriet was weaned at 6 month but refused point blank to eat anything until about 9 months. It may have been we missed a window of opportunity, she certainly is a lot more fussy at three than many of her friends who were weaned at four months and have always eaten everything, but then she would eat anything at 6 months and you can't make a child eat food if they rufuse it so I always found advice like that profoundly unhelpful!