Why do you need a VPN for xdcc? You are not sharing anything, and you had no way to know that something like Fast.X.2023.MULTI.2160p.WEB.H265-LOST was pirated content. All the legal letters are pursuing who was sharing something, not just downloading something

Moreover, in order to have both your IP address and what you downloaded, they would have needed to operate the irc server and the irc bot itself, and that would make them much wrong as it's massively sharing copyrighted content + entrapment of regular users who were just lurking and not wanted to infringe any copyright

Are you sure you actually need a VPN for XDCC? In most countries that I know of, downloading pirated content isn't technically illegal. It's the sharing of that content (i.e. torrenting) that often is.