[abhorrence]

That phrasing is really bad, but probably is trying to make a distinction between the protections afforded by the laws like the Family Medical Leave Act, and how their additional 8 weeks unpaid leave work.

Assuming Basecamp is even covered by the parental leave portions of the FMLA (which they may not be due to size and geographical distribution of the company [1]), someone can't be fired or laid off while on the 12 protected weeks of parental leave. However, in this additional 8 weeks, they can be.

[1] The internet says Basecamp employs 50 people, which is the minimum requirement for a company to be covered by the FMLA. Additionally a given employee is only eligible if at least 50 employees work within 75 miles of where they do.