It really depends on the natural behavior of the particular orchid.
Some phals have a really strong vertical inflorescence, so the growers just reinforce that instead of going against it.
There are phals that have naturally pendulous inflorescence, but some growers still try to train them upwards due to space constraints.
The orchid will do what it wants to do. So if you want a downwards flower display then you will have to do it on a plant that naturally hangs its spike down.
Otherwise the growing tip of the spike will curl upward again as it grows.