Anything that isn't publicly known to exist, and has a similar purpose (research into safeguarding the future of humanity, or philosophy that relates to that future, or whatever). It counts if the Future of Humanity institute reopens and isn't affiliated with Oxford, and similar. It counts if he co-founds, or if he is integral in the creation of said institute without being the official founder. It counts if the institute is called something other than an institute, like an organization or a research group.
If other edge cases exist, please bring them up in the comments :p
looks like it's this thing https://find-and-update.company-information.service.gov.uk/company/15054502/officers
the person who filed the company is someone from the global priorities institute. not clear whether bostrom found it or whether this is just a place he's temporarily working at and wasn't made for the purpose of replacing the FoH institute, but my guess is that it is