In Forza Motorsport titles of the past, Porsche vehicles have been released post-launch as DLC. Now, thanks to a new partnership between Forza devs Turn 10 and Porsche, the cars will be featured in all upcoming Forza games from the get-go.
As an interesting bit of backstory, the reason for this was an exclusivity deal with Porsche and EA for EA's Need for Speed series. As a result, other game companies had to go through RUF, a German car company which makes their own vehicles from Porsche chassis.
You can read the Twitter conversation from Turn 10's Dan Greenawalt here.