Sure things can go wrong (and I’ve seen a lot happen in my life, particularly with non-profits), and maybe that is more likely to happen when an organisation is not just OSM focused, I doubt it though.
If the local community thinks that it is best served by an organisation that isn’t just OSM focused (FOSSGIS, Wikimedia Italia, OSGeo Oceania come to mind), then I’m completely OK with that. But it has to be clear that the LC floats and sinks with that organisation and not have complex illusions of being separate.
If you want independence, then incorporate as a separate organisation.