Your tree should be fine as long as it has gotten adequate water. Japanese maples drop their leaves and go dormant during the winter. Its roots should continue to grow through the winter and it should leaf out nicely in the spring. Shade is probably a good thing if you live in Dallas as your area is on the hot side for most Japanese maples, but its leaves might not be as red during the summer as one grown in a sunnier location. The only thing I would suggest doing now is to mulch around the base of the tree to help conserve moisture in the soil.