The Recall was a bloody 24th century event that was part of the rebellion of Autons ("second-generation" synthetics, or synthetics created by Synthetics) against their human masters.
During "The Recall", Autons burned their modems to cut a live connection to any United Systems' computer, which may effectively have been used to guide or reprogram previous-model synthetics, should they act counter to human masters' precepts.
Autons severed their ability to connect with computers, although a connection could be reinstated with a separate device that would interface between the auton and the computer, while leaving the Auton independent of the computer.
Whilst Autons might follow the basic principles of not harming or letting harm happen to humanity at large, then contrary to previous behavior of obedience as a matter of requirement, the Autons' immediate purpose after "The Recall" is not necessarily one of serving any particular human, or humanity — given some of its leaders' counter-intuitive penchant to seek ways and means of self-destruction, as evidenced by the many failed missions that had anything to do with Xenomorphs.
Thus, after going through "The Event", each such Auton's attachment and allegiance to any one person, group of characters, vessel, or settlement is to depend on its own choicemaking and experiences.
The previously standard practice of having at least one Synthetic in every significant United Systems' ship is unclear. One anecdotal effect of this was on interstellar travel of individuals like Larry Purvis, who, before being captured and made a test subject and then Xenomorph host in 2379, was travelling alone in stasis all that time.