DNA testing at USDA/UC Davis indicates that Vista and "their" VdB are the same. The issue between VdB and Negronne is quite simple. Both have been sold by nurseries under both names, so some VdBs are Negronne and some Negronnes are VdBs. There are a lot of steps between a twig and you getting a tree delivered to your door, and not all of them are well controlled in many cases, so mislabeled plants are very easy to get. That is the "short" story, and what has led to so much name confusion with a whole bunch of varieties.
VdB and Negronne may or may not be the same, but they are very similar. I have several of each, and they are clearly related, but also clearly not identical. But I also have 20+ Celestes, and they are all DNA identical, as well, but clearly are not all identical, either. Welcome to the "fun" known as Figs.