Ubisoft revealed their roadmap for the post-release content that they have planned for The Crew 2. These plans include new vehicles every month, and new content every three months. There are additional perks for those that pick up the Season Pass, some of which are outlined below.
Players looking for the ultimate The Crew 2 experience will be able to do so with the Season Pass including:

It's interesting to note that Ubisoft is calling these planned releases as "Year 1 Content" implying that there may be a second year if things go well for the game. This would be similar to what they have done with games like Rainbow Six: Siege or even Ghost Recon: Wildlands.