Yeah I've been aware of this curious inconsistency for a while now.
Just putting it out there, one of the conceptual/draft versions of the Runeterra map indicated a city called "Old Zuretta" which is in fact somewhere south-ish. But, and pretty big but, this hasn't been officially canonized yet. So its difficult to tell what Narrative's intention with this will be. At this time being it's definitely an error in Renek's bio.
There is a chance, albeit low, that sometime in the future Renketon could have his bio re-updated, just to fix any kinks or small inconsistencies that exist. As over the last year or two, a lot of new world building has been established and sometimes it doesn't quite align completely. Example: Ryze's bio was re-updated recently as originally it suggested he was witness to the destruction of Icathia, whereas now he wasn't even born until long after the city was consumed.