Those plants are just starting to get their new leaves. This says they're alive and growing. It's this new growth that's important, not the old leaves.

If you have the time and effort to spend, you can carefully rake off the old mulch and brown leaves, which can harbor fungus and disease. While you're doing this, you can remove any plants that are obviously dead. You should be ready to lay down new straw or other mulch in case of a late freeze, so you can use it to cover the plants. A freeze when the flowers are starting to open will ruin your crop.

The important thing is to thin and clean out the bed this summer after they fruit, so you're not faced with this problem next spring.