Too much is being made of the self-locking centre gearing set being used in various MLB quattro models. The crown gear version is slightly shorter and slightly lighter than the planetary geared set - all the other components are the same. A crown gear set "grips" slightly more quickly than a planetary set. But it is also more abrupt between releasing and engaging. Fine with lower torque NA engines, less ideal in high torque FI engines. Which is now most of them.
The crown gear set was used in several models following the RS5. But Audi do not specify what type of gear set is being used in various models. You need to crawl underneath to measure housing length, or obtain a parts list. But why bother - my S5 has a planetary gear set, and my A7 has a crown gear set. But I could never pick that up from actually driving them
The centre differential gear set is just one part of the entire system. So "Torsen and not Crown Gear" is making a mountain out of a molehill.
The quoted article is wrong. The change from a Torsen sourced to an Audi design first appeared in 2005 on the RS4. The crown gear differential "option" came later, in 2010. Whether this enabled Audi to avoid paying, or reducing, patent license fees, IDK.
This shift from Torsen supplied to in-house design was 2 years after a Toyota subsidiary had bought Torsen from Robert Bosch (still a major Audi supplier) in 2003.
But JTEKT is "just" an automotive supplier like many others. Their primary business is power steering systems. These operations are best thought of as very advanced machine shops.
See various info here, if interested:
JTEKT Brazil LTDA
I've used the Brazilian office of JTEKT, because it amuses me that it is located at 1200 Avenue Volkswagen Audi
Self-locking center differential ? Audi Technology Portal
Crown gear differential ? Audi Technology Portal
Drivetrain ? Audi Technology Portal