Maybe a startup has a favorable standard exit package that they offer to all departing employees or executives, such as 6 months salary continuation and an extended option exercise period. If so, it’s likely offered so the startup can be seen as employee-friendly and maintain a good relationship / reputation for ongoing recruitment and retention purposes. 

But if they do not, what would make them offer this - or something more favorable - to you?

It’s not obvious.

I’m not trying to discourage startup professionals from expecting and asking for favorable terms. Individuals do sometimes get astonishingly generous startup separation packages not included in their original offer letters, such as accelerated vesting, long salary continuation periods, bonus payouts, early liquidity opportunities, and variations to their standard option exercise period worth millions of dollars. 

But these extra-favorable terms are usually based on one of two extremes:

1. The founders’ or other leaders’ desire to do right by someone who helped build the company, based on a “boys club” mentality (regardless of the sex or gender of the person). The departing employee or executive is considered on the “inside” and so they want to do right by them as part of the relationship.

2. The company’s concern about the costs or other downsides of possible litigation of legal claims.

Both of these depend on the individual understanding their leverage and being willing to press their leverage.