Tool is a headliner there. They wrote that in press release, something like "we have 6 headliners so far - Tool, Muse, Pink, Florence, Mumford and The Cure"
Tool is relevant. They'll have a new album out next year and they've been playing new songs live and it will sell way more than The National one. Also The National is touring their latest album to death. It's not really an inspiring booking for 2019.
And don't get me wrong. I like both of them. Actually I like The National way more but Tool is way bigger booking than them and the fact they didn't tour Europe since 2007 alone makes them relevant