Board Game Arena

Basically what the title says. I'd like a bit more variety when playing the arena, it's it possible to play the expansions when playing the arena?

No you can't. Arena mode has set rules for each game. In carcassone it is without expansions.

Each season the settings get set, and right now they are set by a group of players who play the most. so for it it change they would need to decide that.