This warning is reported because macOS is preventing CopyQueue from writing the com.apple.quarantine extended attribute to the destination file. This is a common warning and has no negative impact.
com.apple.quarantine is an extended attribute that macOS uses to mark files that originated from the internet or another untrusted source. It’s used by macOS security features such as Gatekeeper to decide whether to warn the user when opening a file. As a security flag, macOS doesn't allow third party apps to manipulate it.
CopyQueue attempts to replicate all extended attributes from the source file to the destination file, but it isn't always possible. With attributes such as com.apple.quarantine, macOS will set the extended attribute itself if necessary, but the file will be completely usable if it doesn't have this attribute set.