Double-checking my understanding of the interaction between these two rules, especially since
GK Librarians will be very common nowadays.
Psychic Focus grants access to the Primaris power if all powers are generated from the same Psychic Discipline. Psychic Focus is lost if the psyker gains access to a power from a different Psychic Focus (excepting Force, etc.) at any point during the game.
Liber Daemonica allows the bearer to generate an additional Psychic Power from the Daemonology: Sanctic Psychic Focus.
It seems fairly clear that if you generate all of your powers from Divination (for example) and then roll the additional power from the Liber Daemonica (on Sanctic), you would no longer have Psychic Focus and lose access to the Divination Primaris power (unless you traded one of your Divination rolls for it specifically).
Am I missing anything special regarding this interaction that would make this not the case? Seems pretty straightforward to me.
Cheers,
DoW