I guess there are a couple of things. There are contracts signed after the budget is announced. According to the way it's been described in the budget documents, as long as payment has been made in full before January 2018, it would still apply. After that date, it wouldn't. The confusion for us lies in how the business works and how deals are signed. There is a primary deal and there are secondary contracts that flow from it.
On May 18th, 2017. See this statement in context.