When reached for comment, a spokesperson for Ferrero said the following: "We have recently carried out a fine-tuning in line with the evolution of consumers’ tastes. The quality, safety, sourcing and all other characteristics of the Nutella ingredients remain the same. The ingredient list can always be found on the jar and on the Nutella website. From a nutritional point of view, all relevant aspects remain similar."
It's also important to note that we only know for sure that this applies to Nutella overseas, which is different from US Nutella. We haven't been able to confirm whether a similar change was made here.
Update: The following statement was provided by a spokesperson for Ferrero.
“We produce Nutella with the same care all over the world. And we make sure our consumers are fully satisfied with the unique Nutella experience through frequent and robust taste tests.
"The recent fine-tuning we performed is only a minor change. Concretely in the US, the content of hazelnuts, cocoa, sugar and palm oil remains unchanged. The fine-tuning consists of substituting whey powder with an equivalent quantity (2.1g/100g total product) of milk powder (from 6.6% to 8.7% of total product). This enables us to improve the overall quality of the milk content and to ensure a better consistency of our unique taste over time.
"That’s all. Our recipe contains 7 simple ingredients, with no colors or preservatives. The nutritional values remain practically unchanged."
H/t Grub Street