Of course, one can stay sober without yoga and meditation. It's just that if you want to lift yourself up out of the energy of addiction and break through to a new level of strength and awareness, one will have to adopt a practice that continues the detoxification process on a much deeper level.
In 1991, Tommy Rosen got sober and found the path of 12-step recovery. That freedom from addiction required several key elements: a spiritual path, community support, yoga, meditation, and a conscious diet.
Yoga for recovery recognizes the need to connect the story of the body with the reason of the mind. Often people abuse their bodies because they don't feel comfortable in their skins. Yoga can help change that.