While nothing official from AMC or Danai Gurira herself has been announced about her appearing in the movies at the time of writing, the Walking Dead comics prevent the perfect way to write Michonne out without killing her off, and even reuniting her with her lost love.
The movies that are now in the works mean another way to write out characters, and the odds are quite good that however Michonne leaves the main action of The Walking Dead, she’ll be back in the movies.