When a newly planted shrub loses leaves suddenly it is usually due to transplant shock. This catch all term just means the plant suffered from the move most likely due to heat, lack of water or suddenly being exposed to more sunlight than it was used to. The rest of the shrub looks okay so I would not be too concerned. You can snip off the branch that has no leaves or leave this pruning until spring. Your new shrubs should settle in and thrive in a couple of months. Meanwhile, keep the soil moist and use an umbrella to add shade if you think you planted in a hot and sunny spot. Keep growing, Marianne Binetti