That's in this bill before you, and that's right. Child benefits, like some other income benefits, work on a July to June schedule. In July 2018 it will be based on your 2017 income. Both the maximum benefits and the income thresholds will be indexed at 1.5%, which is the indexation that applies to the 2018 tax year.
On April 24th, 2018. See this statement in context.