The decentralized autonomous organization (DAO) made the decision as a means of mitigating the Maker protocol’s exposure to the beleaguered staking and lending platform in case Celsius goes belly up and implodes the staked Ether (stETH) peg as well. https://cointelegraph.com/news/maker-cuts-off-aave-s-dai-supply-as-fallout-from-celsius-continues