Neons. as with most other commonly kept fish, really do not and cannot read pH and are quite adaptable to water conditions other than for breeding.
The info given specifying the addition of salt to a neon tank is horrible. Blackwater fish are not just from soft water (=low GH, which their eggs require but the fish do not), they are from low TDS water. Adding salt boosts the TDS markedly. It is a contradiction in terms to specify soft water and then add salt. That to me is a dead give-away that the original author of that script did not understand water or fish physiology at all.