As far as I know, ETH and BTC have different networks, so it won't make sense when the ethereum merge in the future will affect bitcoin fees because they both have different networks.
He may only mispel. it's ethereum transaction fees and not bitcoin fees. If someone was making a mistake when typing something and it was just a common thing. As long as we can understand what was the main purpose from his thread correctly and that's more than enough.
Consensus it the main concern in this case but sometime people are never trying to read what contained in EIP. They are talking about something that they didn't know about.