Unfortunately, DI carbon buildup spans many different engines and manufacturers. Some are better than others, but many DI engines from Audi, Mazda, BMW, and others still require carbon cleaning due to the nature of DI setups.
In the video below, it shows how gas flows over the intake valve into the cylinder before firing. With direct injection, there is no gas moving over that valve. Modern gasoline blends contain detergents (like Techron and the like) which clean these valves and keep carbon from building up.
Some manufacturers have included supplemental port injection of gasoline with their DI engines for the sole reason of combating this issue.
https://www.youtube.com/watch?v=aOksuRwfovw