Acer plamatum leaf shapes can be extremely variable, both between the various divisions of the species as well as within the divisions. Also, young trees may exhibit juvenile foliage that can be quite different in appearance from more mature foliage....even well-established trees will often throw out shoots of juvenile foliage during the growing season.

Variability of Japanese maple leaf shapes

While they may not be exact examples of the "classic" JM leaf shape, they sure look like JM leaves to me.