"Institutional knowledge" is neither institutional nor knowledge until it's documented and reproducible. Experience limited to the insides of people's heads is merely lore.
The VP's organizational philosophy turns on this upside-down phrase. The full formula is, "Turnover can't be allowed because of the loss of institutional knowledge." But this is an incantation, a manipulative combination of words to obscure the truth, that her own inept management has fostered an organizational culture where documentation doesn't exist, and the real reason for dreading staff loss is because no-else has any idea what each other knows.
In the end they're all prisoners. The veterans can't leave because they've stagnated so long they're no longer employable. They can't be replaced because of the lack of documentation. It all runs on muscle memory, and patronage, and interpersonal arrangements like little treaties between kingdoms, informal and uncoordinated, immune to evolution or change.