Can you get demoted in BJJ?

The BJJ community generally does not support demotion. Your belt represents what you have achieved and learned, even if your current performance does not match your peak. After a long break from training, your techniques may be rusty, but the knowledge is still there and returns relatively quickly. Some notable cases of voluntary demotion have occurred when black belts returned after 10 or more years away and felt uncomfortable representing black belt level. This is respected as a personal choice but not expected. A more common situation is when someone changes gyms and their new instructor has different standards. The new instructor cannot officially demote someone but might privately consider them below the level their belt suggests. In practice, most people retain their belt and work to meet the new gym standards. The most important thing is that you train honestly and continue developing your skills regardless of what color belt is around your waist.