In life, certainly.
So that's what you mean, the "cartilaginous episternum" of (older) Paul reconstructions. The 1998 JVP paper on tyrannosaurid furculae has shown that there was nothing between the coracoids because the coracoids touched, that's the only thing furcula and sternum were broad enough for. There remains a bone-free triangle between sternum and coracoids, however; maybe a cartilaginous extension of the sternum was in there. That's also where Iguanodon's irregular "intersternal ossification" is.