I want to point out that at no point does it say prototyping two sprites creates a black hole, it was just fanon that that was how Caliborn's situation happened before it was explained. When Hussie explained it in the comic, he stated that the game's nature changed and caused the kernelsprite to collapse, not that Calliope and Caliborn's sprites prototyped each other. (I searched "black hole" into the Act 6 search to find this)

Yes it’s fanon, but Caliborn’s sprite was flashing his and Calliope’s colors much like Jasprose does with Rose and Roxy’s colors. Plus prototyping two empty kernels with each other is essentially dividing by zero which theoretically creates a black hole so it just makes sense. But you’re right, it’s entirely not canon.