Freestyle away - the combinations are examples, not laws. In our own course the white shell carried cream-cheese ganache with cherry confi and the dark carried rum ganache... as demonstrations of technique, not eternal pairings. Any well-made ganache or confi can sit in any tempered shell.
The rules that DO bind, regardless of pairing: filling at the right consistency (pipeable, sets firm enough to cap), at room temperature going in, below the shell rim so the cap seals clean, and capped properly. Those are structural. Flavour is entirely your jurisdiction.
Some pairing wisdom rather than rules: dark shells flatter tart and boozy fillings (the bitterness frames them), white shells love fruity and tangy centres (their sweetness needs the cut), milk goes with everything like a labrador. Break any of this deliberately and taste - that's literally how signature chocolates happen 🍫
