Yes cutting the power to the cameras could cause premature damage to them.

Depending on where the OP is located and the cameras they want to turn off are installed it could have very serious effects. cameras installed outside in a northern climate, camera turned off in the evening and temps drop below freezing. During that temp change there will be moisture created on the electronics and if it gets cold enough could cause shorts on the boards when power is applied. In Canada we get very heavy dew in the fall and with temps getting colder it isn't uncommon to have heavy frost in the mornings starting this time of year. I would not be switching or recommend switching exterior cameras off from October to May as they might not turn on again.

If the OP is switching internal cameras than the risk of failure is reduced as you are in a climatized area with little worry of condensation buildup on the electronics.