I think it's a good idea to make all ARs mandatory in order to access the roulette. I'd go as far as saying it'd be good if ARs and NRs were obligatory to do after you've finished the entire expansion or maybe an expansion after if you wanna give people some wiggle room, and the reason is super simple: so they can actually grab that lore and do something with it other than seasonal character cameos. At some point they gotta stop pretending Gaia only exists if you did the Eden quests...