Gorillaz it is, a gap between norway and london 10 to 19 August. Maybe co-headlining with tame impala than?
Justin bieber it is, gap between sweden 09 august and 04 september. Would perfectly fit.
So either the set of headliners is than complete or there are some co-headlining options. Either way; My guess at this moment.
Dua Lipa - Arctic Monkeys - Kings of Leon - Justin Bieber - Tame Impala - Gorillaz.