I am also not a car engineer, but from my reading of "Federal Motor Vehicle Safety Standards; Door Locks and Door Retention Components" [1] it is the latching that is meant to prevent the door opening, not the locks. However, even many modern cars have a mechanical linkage from the handle to the door. In a crash the mechanical linkage, particularly older style tension-type linkages, could unlatch the door when your body hit the door from the inside and physically moved the linkage [2]. A lot of doors use electric actuators now [3], and linkages are much better designed, but it seems like it could still be an issue, in theory.

[1] https://www.federalregister.gov/documents/2007/02/06/07-517/...

[2] http://www.autosafetyexpert.com/defect_doorlatch.php

[3] https://bestsellingcarsblog.com/2023/10/media-post-actuator-...