It's very likely that the "Chinese mother" edit was an intentional fabrication. If so, it is difficult to understand a motivation for that other than usual "movement" stupidity.
That latter possibility is the major point. The ancestry of some pop culture figure is really not important at all. The fact that someone thought it necessary to essentially vandalize a Wikipedia page with fabricated nonsense to alter the public perception of that ancestry is important. The possibility of a "movement" connection to that racial lying is also important.