Yep, but in this model the sidechain has its own miners who produce blocks and collect fees.

The multiple sidechains then compete in an auction to pay the highest Bitcoin transaction fee so that their hash is included in the base layer blockchain. This is only required to peg out of the sidechain and withdraw BTC back to the base layer.

In your example, the CBDC administrators could censor any transaction they like within their sidechain and do not require participation or collusion from Bitcoin miners.