Clause 47 of the bill introduces the definition of “ministerial adviser”. Since it's a new definition, it's just a technical amendment stating that the effects are not retroactive. As a result, if people were previously included in the definition of what has just been created, they will not be affected by the new effects of the legislation. This amendment therefore states that the effects are proactive, not retroactive.
On November 8th, 2017. See this statement in context.