Open source projects abandoned by founding companies have a better track record than SaaS projects abandoned by founding companies.

Anybody who is interested can maintain it. If it has a large number of people actively using it to conduct business on a daily basis, somebody will maintain it. If it's big enough that lack of maintenance would be a problem, it won't be a problem.

Most of us were working on OB for free before OB1. If OB1 were to fail I think many of us would continue to work on OB either at another OB-based company or just back on our own.