Yes, Warbuton seems to admit The Voice is what helped them though the year, but I don’t believe that Nine handing it to them was a big miscalculation. Only Seven gave the show a nice refresh - Nine knew they couldn’t revive it with how long it had been on the network, and it was costing them. It would have only hurt Nine more to keep it.
It’s just lucky for Seven that they managed to do good with it.
Anyway, with MKR also being mentioned in the article, it looks like Seven is opting to stop the drama that unfolded in previous seasons. Their “original recipe” might do them well as the simplified The Voice did.