Again, this is a response to the constantly changing concentrations of plant growth regulators. From now until fall, the objective of the tree is to prepare for winter. During fall the trees are storing up food and energy reserves which are needed for next spring's growth. Forcing new growth occupies the plant and delays the energy-storage process. The shortening days and the reduction in sunlight cause another change in the driving mechanism, and this stimulates dormancy in the tree.
Dormancy is a period of rest and inactivity.
Changing the conditions around the tree may alter the time of year that the tree goes into dormancy. New growth produced at this time of year will have little chance to prepare itself for winter, and will most likely die from winterkill. You may argue that watering in fall is recommended to prevent winter desiccation. Agreed, but the timing of the water is important. Late October watering is recommended to prevent winter desiccation.