Yeah, if (BIG if) they actually generate demand for it, mass producing power generators will be easier to do than mass producing planes. Starlink was SpaceX's way to generate their own demand - they have a vision of scaling up rocket launchers, but without Starlink there wouldn't be enough demand for it. Likewise I can imagine there won't be much demand for hypersonic airplanes, not enough to run a business. At least the Concorde was only one of several models that the manufacturers produced, so it wasn't their only product.