Nothing amazing about this. They already found a T-Rex leg-bone with fresh red blood cells and flexible soft tissue. This is a natural follow-on. And btw, that’s not a kangaroo’s head.
After dissolving away the mineral portion of the bone with weak acid, various types of flexible structures were recovered. They conform to the microscopic pores of the bone in which they had resided, so they are mainly viewed under a microscope. These structures include transparent, branching hollow vessels corresponding to the blood vessels found in modern animals (e.g. ostriches), and also what look like modern osteocyte (bone) cells. Various biochemical tests have indicated that these structures are composed of animal protein, showing that they derive from the original dinosaur tissue, as opposed to being merely biofilms produced by microbes which invaded the bone pores.
https://biologos.org/blogs/jim-stump-faith-and-science-seeking-understanding/soft-tissue-in-dinosaur-bones-what-does-the-evidence-really-say
It could be if kangaroos were misnamed and are actually something else.......