Imagine that Vault 111 is for Military/Government program personnel.
There is someone in the vault who is essentially a genius on the level of Dr. Braun in cryostasis. The institute wants the secrets they hold.
Due to a problem with the cryonic stasis reviving process, people cannot be re-animated once they are put in. They turn to mush during the thaw (or something similar). so reviving them is a useless endeavor. They can however, scan people in cyronic stasis. Mapping their brains down to the neuron states, perfectly.
an android brain is built off of these specifications, enabling the brain to have every memory that the subject had, while alive. From there it is put into a body.
At first Institute scientists told the androids what they were. The perfect image of the subject mind could not process, and rejected this notion. They refused to co-operate. Or became violent or self destructive. So, this method was deemed not only useless, but counter productive. And the droid minds were wiped.
The best way they found, going forward, was to stage the androids as subjects being revived, one at a time. Letting the android think they were actually a person who emerged from the vault was much more organic for the android. From there, a branch of the Synth retention bureau is sent to meet them and to win them over, bringing them into the fold at the institute.