Reproduction steps:
1. Open any new or existing project
2. Add a Playable Director to any GameObject in the Hierarchy
3. Create a Timeline Asset
4. Attach it to the previously created Playable Director

Expected result: Playable Name and Icon will be changed accordingly to the Timeline Asset
Actual result: Playable Name stays "None" and Icon stays default

Reproducible with 2020.1.0a15
Not reproducible with: 2017.4.35f1, 2018.4.13f1, 2019.2.14f1, 2019.3.0b12, 2020.1.0a14

Note: even if Timeline Asset was attached in previous versions, the Icon displayed upon upgrade becomes default Icon and Name is set to "None". Everything else is working perfectly (the Timeline Asset and Playable Director function as intended, tested by playing a .mp3)