This will only accelerate the trend to automating away these jobs. E.g., serve your own soda -- it is cheaper than having a human make the drink for you. When humans are more expensive than machines, they are replaced.
I think what will happen is the complete opposite, fast food chains will start hiring more capable workers because that will be the big differentiator. Why would I go to a McDonalds, or Wendy's or Burger King? I'll go to which ever one has the polite and competent people taking my order.
Sure they will all jump on the automation bandwagon, but when everyone is doing it, some one is going to go back to "personalized" service as a differentiator.
Overall I am glad this is happening - their should be no reason why a person who works 40 hours a week in the wealthiest country ever known to be below the poverty line. Just doesn't make sense. Both economically, and from a human rights perspective.
That said, the sooner we can automate away jobs like these and move to a basic income, the better.