I do not think July 2018 is a due date for growers, it is a due date on the legislative side to put in place the legal framework for legalizing marijuana in Canada.
Here is a reference YouTube clip for your information:
I would think Health Canada will welcome any MMJ grower to add to the production input once they have passed all stages and inspections to be compliant before becoming a licensed MMJ grower.
Once finance is approved, AMS will need to get through the final stage and inspections before becoming a licensed MMJ grower.