It looks like you're asking for a useful informational paper or release note document regarding an update for Forza Horizon 5 (from version v1.634.818.0 to v1.642.644.0 ), including references to DLC.
: These updates usually include new cars, Series event data, and technical fixes for the game's engine or online connectivity. Key Change FH5-Update.v1.634.818.0.to.v1.642.644.0-with-DL...