Maybe we’re all reading too much into the NDA. It is exactly what it says, a nondisclosure. It doesn’t mean a deal is made, it just means they can’t talk about it.
The company may have looked at it and said it was not a deal they wanted.
They may want more time.
They might want to create their own test or more info that is not available yet.
A deal typically takes from 3 to 9 months.