No, Медали are there forever. Once Ты have it, it can only upgrade.
Ты can even unfan a club Ты have a medal in, Ты will lose that medal, but if Ты Фан that club again Ты get that medal back after some time. (I know this because I tested it myself)
Ты can't lose a medal just because you're not as active as Ты used to be.
The most you'll lose is a spot on the вверх Current Contributions.
