Reproduction steps:
1. Open the attached project.
2. Select Assets > Build Asset Bundles > iOS in the menu bar.
3. Wait until bundles are built.
4. Check the Editor.log.

5.3: As expected, includes detailed information about % break down for each asset bundle and each asset included
5.4: Includes a break down of the assets included, but is not split between which asset bundle includes which.
5.5+: Does have the headers, but contains no information

Related to:
case: 823154

Note:
Logs attached in the edit.

Regression introduced in:
5.5
partially 5.4

Reproduced in:
5.4.5f1, 5.5.2p2, 5.6.0b1, 2017.1.0a3

Not reproducible in:
5.3.8f1