What I expected to happen...

I renamed a stack of Ender Chests to "Netherending Chests™" as a promotional item for my inRealm "Netherending Store™". I expected them to retain this name change.

What actually happened was...

They were renamed correctly, and when placed retained the name and correctly displayed the name in the GUI when accessed. However, when broken with a Silk Touch pick, they had reverted to being "standard" Ender Chests.

Steps to reproduce:
1. Rename an Ender Chest on an anvil.

2. Place said renamed Ender Chest.

3. Break said renamed Ender Chest with a Silk Touch pick.

4. Pick up the resulting item and observe that its name is now "Ender Chest", and not what you renamed it to.