Newsline is a strange choice for a backup region. Though I guess Points West and Spotlight are backups for each other (as we've seen in the past) and Midlands Today and East Midlands Today are naturally backups for each other.
I'd imagine NWT would be paired with one of the Look North's.
Therefore it leaves Wales a bit on it's todd, just like NI so I guess that's the reasoning behind it.
January 9th 1989 - December 3rd 2006