Steps to reproduce:
1.Open attached 'TimelineScaleIssue.zip' Unity project
2.Open ‘Timeline_scale_issue' scene
3.Enter Play mode

Expected results:
Models with reduced scale (0.5, 0.5, 0.5) move with a smaller velocity than normal scale (1, 1, 1) models.
Actual results:
Model with reduced scale which was animated in Timeline moves with the same velocity as a normal scale model animated in Timeline.

Reproduced in: 2017.3.0a1, 2017.2.0b4, 2017.1.0p2, 2017.1.0f3, 2017.1.0b1

Note: Could not test earlier versions because Timeline was introduced in 2017.1.0b1