Car manufacturers don't take these steps hastily, and German brands in particular are renowned for brand (over-)management.
Maybe Audi is kicking against BMW, to become more engineered, more sophisticated and, dare I say it, more Germanic. There is also a sense of preparing the ground for a big marketing push to celebrate the marque's upcoming centenary.
What's really interesting is that no one seems to have been talking about it. Even hardcore Audi bloggers haven't said a thing online. Why?
It boils down to the fact that it doesn't really matter that much to them. The rings stay - everything is OK. Audi feels like a brand that's on the up, with a clear sense of what it is and where it is going. The brand is about the product, the experience and the service, not the logo.
Interesting that when Vauxhall did a similar tweak (from a position of business underperformance and brand weakness) it was lambasted. So for Audi this goes down as one of those small tweaks that people don't really notice but when you see all the tweaks through a hundred years you can enjoy the metamorphosis in a nostalgic way.
If Audi had dropped the famous iconic four rings then the lynch squad would be out in force.