Erm...I may be missing summat, but....
My take would be that surely that statement in itself is pretty accepted, if you (as I think most interested peeps do) that hunting/gathering was the older of the 2 lifestyles.
If I understand the article correctly tho, the 'new' bit is that once farming arrived, the people that brought it don't seem to have added DNA to the European DNA make up. Which presumably means either that Europeans took on the farming idea but didn't 'hob-nob' (oo-er!) with the 'incomers', or that the 'incomers' kept apart. Which is surprising, but I don't know NEARLY enough about genetics to know HOW surprising!
But, as I say, I may well be missing summat!
love
Moth