@MyNewBeginning I would need to speak Korean to know if the saying actually exists in the Korean language, as your 1st sentence asserts. The 1st sentence as written doesn't imply either way about the truthfulness of there being one-sided love between mothers and sons--it only assets that the saying exists in the Korean language.
Your question didn't ask "Could the saying be true?" It asked "Could this be true?", in which under the rules of English grammar as I understand them, "this" refers to your entire 1st sentence.
So, as both your 1st sentence and your question are originally written, I do need to know Korean to properly answer your question.