Why is this 737 MAX 8 still flying? I just saw a plane overhead that was flying unusual low and it turns out it was a 737 MAX 8 that left from the Boeing factory in Renton.

https://fr24.com/BOE867/1fdcadbf

Are planes that are not yet operated by airlines exempt from being grounded?
Emergency order issued by the FAA allows for special flights including production flights testing, ferry etc.
The order is available on the FAA website.