Interesting thought, but I'd say such superposition already exists.

If there is no CT, there is still no mapping between sats in each input and sats in each output. (Because satoshis don't exist, any more than an inch 'exists'). Unambiguous mapping of input to output only exists for 1 in 1 out.

Any other interpretation like FIFO is just something an observer makes up. Not just that, but it clearly has zero correlation with actual chains of ownership.

It's true that CT makes this arbitrary assignation either impossible or much harder. You could still do it by publically sharing info (which is verifiable). It would be stupid, of course, because you could just choose to not use CT.