Yes, motors will be unhappy
Common induction motors running at reduced voltage tend to draw more current, leading to more heat generation, and possible overheating. Air conditioner, refrigerator, dishwasher, washing machine, etc.
Light bulbs, heaters, and similar resistive loads running at a voltage 10% low will just produce 20%less power. Annoying, but rarely dangerous.
A modern APFC power supply won't care.