And this was my point. If they had done this more surreptitiously, it likely wouldn't have been noticed as quickly. The fact it was planned out ahead and will happen automatically, barring a change in government to repeal it, gives businesses the business case to make these changes asap, with the lead-in time the law has given them. However, if they had simply increased the minimum wage by $.5-$1 per year for each of the next however many years it takes to get to $15/hr, businesses would not have the same business case for automation until it got to $12-$14/hr, and that would have spurred the automation technology to get over their last hurdles at that time, and then the roll-out, and, yes, minimum wage would have been $16-$18 before the automation would have been there.
Conversely, had the minimum wage been frozen instead for the next 10 years, automation would be even further out. I'm not saying this as an alternate solution, just pointing out that an inevitability such as automation is seriously moved up by announcing it as if with a bullhorn.
Much like getting warning that your employer is going to get rid of you by the end of the year - you don't wait for the pink slip before you start job searching in earnest, and a business knowing that its labour costs are going to increase by significant amounts over a relatively short period of time will start looking at alternatives at its earliest opportunity, once it knows where the costs will be and over what time frame.