AFAIK there hasn't been any delay announced for Udacity courses. Can you please cite the source, from where you got this info.

They are not delayed. I got emails yesterday saying they start Feb 20

Udacity's CS101 is still slated for Feb 20 from its website

I don't want to speculate on why, but I suspect the two are strongly related.

I'm taking their self-driving car course right now, it's in the second week.