Can a Mystic swap out their Bonus Disciplines for some that aren’t from their Order?

The Mystic is an Unearthed Arcana class in D&D 5th Edition. All the Mystic Orders (subclasses) except the Soul Knife get Bonus Disciplines :

At 1st level, you learn two additional psionic disciplines of your choice. They must be chosen from among [your Order’s] disciplines.

Regular disciplines can be swapped out :

In addition, whenever you gain a level in this class, you can replace one discipline you know with a different one of your choice.

Can the Bonus Disciplines also be swapped out, even for replacements that aren’t from the Order ?