Issues would come up when the license expired. If XenForo just ceased to exist, we would be merrily rolling along, no issues, getting maintenance from some of the XenForo professionals (in my case) or tweaking it yourself if adept. If someone else owned XenForo, don't know what happens with active forum with out of date license. Someone else can answer that, just no upgrades or support or is their some kind of shutdown DNA in the code?
