Volkswagen's explicit motivation is to improve management recruitment – making sure the company isn't losing out on candidates for important positions because they can't speak German – and that's inherently sensible in a globalized economy. Particularly considering, like it or lump it, that English is the lingua franca of said global economy. It also should make it inherently easier to communicate between its world-wide subsidiaries and coordinate operations.
It's hard to say for sure if this will have any impact on the consumer, although it's easy to see the benefits if, say, VW Group hires some American product planners or engineers and they push for features and designs that more closely suit American needs. After all, the US is a hugely important market for any manufacturer, and so the switch to English almost certainly has something to do with the outsized influence of the US in the global economy. And there doesn't seem to be a downside from a purely rational perspective, although it could mean that the Group's corporate culture becomes less German. Whether that's a good or a bad thing depends on your perspective.