I guess these are from Aviation Partners? This was the outfit which designed the blended winglets for 737s (and others), got bought by Boeing if I recall right (becoming APB). They had some patents on blended winglets, so I imagine would be difficult for Airbus to do this without APB. They announced in December that they were investigating blended winglets, so most probably this is the outcome of that.
By the way, 3.5% or 5% is huge. 15% is amazing (and probably unbelievable).