If you use non scientific names, use at the least the full name and don't talk about species. There is only one valid demasoni species in lake Malawi at the moment and that is Chindongo demasoni.
Fish taxonomy is messy. The two look anlike except for size and personality. One is a gentle giant, the other is a dwarf bulldog. Why is it called dolphin without a hump.
Just because the taxonomy is messy in your eyes, it justfies spreading misinformation? What logic is that?
Chindongo is differentiated by five different morphological features from Pseudotropheus. That's more than most other closely related genera can even dream of.
Btw M. sp "dolphin" is just a provisional name to work with until it gets properly described. They could have called also M. sp. Apache helicopter or what ever. They decided to call it like that and most people followed it because it's a total waste of time to argue for provisional species names.