I've never worked for a startup, but when my company leaves a long-standing position open, it usually means that there's some work sitting on the back burner that isn't important enough to make it on to an existing employee's task list. Even in my small group, there's plenty of work that would be "nice to have", but isn't mission critical. If we find the right person to do some of that work, we will hire them on a short-term contract to do the work. If we don't find the right person, one of us will get to it eventually.

I have a feeling this isn't any different at a startup.