Are the restaked tokens being pooled in a centralized account?

No. The restaked assets remain self-custodied by the user on each L1 client-chain. The locking, unlocking, slashing, and reward operations are controlled by the decentralized Exocore protocol, which is secured by the network of third-party Exocore validators. With this decentralized design, no central entity can ever take custody of the restaked assets. The crypto-economic security itself is pooled based on the collective voting power of the restaked assets on the Exocore system.