Obviously, but assumes absolute space unnecessarily as this is trivially true in Galilean and Special Relativity also, and works with any two objects at any two speeds provided the event where the objects coincide is in the future. i.e. You aren't doing physics but a trivial description of motion. Better to write: light is always observed to travel at c, independent of the relative motion between observer and source and observer and destination, and independent of the measurements of any other observer who may also be in relative motion with the original observer and yet will still measure the speed as c. Again, you say absolute, but cannot possibly measure absolute.And in fact the only physical examples you give are of relative motion, not absolute. ... as measured by a particular observer. It's only when you consider the viewpoint of a different observer that the core of Relativity can be tested.