From the visible characters of the few remaining leaves it looks like you are asking about Trachelospermum asiaticum. No, it is not usual for this evergreen plant to have almost no leaves, at any time of the year. Pop them out and look at the soil they came in, and the soil around the planting holes to see if it was a soil moisture problem.

If the existing ~natural soil is a damp heavy clay and you planted them in pockets of amended or replaced soil you may even find that the soil inside the holes was collecting water.

Otherwise the timing of the planting and the way the tops are almost entirely bare, yet with a few live leaves out at the tip - or otherwise closer to the ground than most of the rest - might point to winter cold injury.

Our T. asiaticum (several varieties) also defoliated this winter and are starting to grow leaves right now. Some are in very wet locations.

I appreciate the information!