The distinction between the two is considered irrelevant in this case. The author mentions that if they have a spendable HTLC output and gain knowledge of their counterparty's commitment transaction from the network's mempools, the spend can be malleable and used as a Child Pays for Parent (CPFP). In the case of anchor channels, where both parties have balance outputs or pending HTLCs, there are two anchor outputs. However, in the case of pre-anchor, legacy channels, the counterparty's commitment transaction would need to be attached with a fee below the minimum mempool fee for the replacement cycling to occur during network congestion.

The author then introduces the concept of a future world with package relay deployed at the peer-to-peer (p2p) level and an anchor output on the Lightning side. In this scenario, the most advanced replacement, as illustrated in the test (where the commitment has an anchor output - see L125), can occur. This implies that the replacement mechanism is more robust and efficient in this future world setup.

Overall, the email highlights the different scenarios and considerations regarding anchor channels and pre-anchor channels in the Lightning Network, emphasizing the potential impact of network congestion and the possibilities offered by future advancements such as package relay deployment and anchor outputs.