https://twitter.com/moobeat/status/1275607623166017538
As of today's PBE cycle there's files on PBE for a reskinned Nexus Blitz map. Riot stated earlier this year that Nexus Blitz would be returning this summer as part of an event, and they've also teased a big "summer festival" event coming this summer, which seems to be related to the two new upcoming champions. Seems the temporary return of Nexus Blitz will be tied to that event as well!