The argument points to a familiar usage of “son”: an expression of love, special proximity or approval. Such figurative language does not establish a biological parent-child relationship.
A teacher may affectionately call a student “my son.” The student neither becomes a genealogical descendant nor a part of the teacher’s substance. This is a linguistic illustration only; it is not independent proof about the exact intention of any sacred passage.
The conclusion is modest but important. A demonstrable figurative usage shows that a title can carry more than one meaning. Establishing its meaning in a specific text still requires context, conventional usage and corroborating evidence.