How to reproduce:
1. Download attached project and open "A" scene
2. Enter Play Mode and press "Space" with keyboard (it will load "SampleScene" in "AssetBundles/s", simple scene will play a timeline loop)
3. Press "Space" again (will return from SampleScene to "A" scene)
4. Check Profiler -> Scene Memory -> MonoBehaviour , AnimationPlayableAsset still in memory
5. Repeat 2 -> 4 steps and Check Profiler, AnimationPlayableAsset will instance more than once

Actual result: Load one timeline in the scene via AssetBundle and then switch to another scene, cause AnimationPlayableAsset remains in memory

Reproduced with: 2018.1.0b7, 2018.2.0a1 (210ec0022b93)