It's just silly that startups will go months without filling a position so they can avoid spending a week on a person that they might need to fire. This is an example of a premature optimization. A problem faced by less than 1% of companies nationwide is not something you need to worry about. It would be like leasing the top floor of an office building in Silicon Valley for top dollar because you heard that NYC occasionally floods in the winter.

If someone is in a protected class and they get fired within the first week, does anyone really think they'll win a lawsuit alleging discrimination? Does anyone actually think they'd get beyond a motion to dismiss (usually the first motion filed by a defendant)? If the employer was discriminating against protected classes they wouldn't have hired the employee in the first place. These types of claims are quickly dismissed and usually incur minimal legal fees.