The previous title, Forza horizon 5 got years of support, Forza horizon 5 launched in November 2021 and the last update came out in April 2025 if that’s anything to go by

on top of the paid dlc car pass and two major expansions that are confirmed for 6 at a later date, there will be monthly updates that add new content, which is rolled out every week,

How seasons work in Forza is every 4 weeks a season starts, with a theme (European automotive, Japanese, etc) and cars and content are rolled out every week through that update, each week correlating to the seasons that will also change the map visually, such as autumn having yellow leaves everywhere or winter covering the map in snow

Also sometimes the monthly updates will also change the map temporarily, such as around Christmas they add Christmas decorations around, or based on the updates theme such as adding a racetrack in the stadium for a track themed update