One thing to note here is that "Reunion" is quite ambiguous on whether Worf knew about Alexander's existence or not: there is actually zero dialogue on that subject.
Huh?
K'EHLEYR: I just thought you might want to talk. A few minutes ago, you looked like someone with a question to ask.
WORF: Must I ask the question?
K'EHLEYR: Yes. You must.
K'EHLEYR: What should I tell Alexander... that he has no father?
K'EHLEYR: Why the sudden concern? You won't even acknowledge that he's yours.
WORF: Why did you not tell me?
K'EHLEYR: And what would you have done? (Pause) That's right... you would have insisted that we take the oath... just as tradition would demand.
WORF: You should not have kept this from me.
K'EHLEYR: Well, now you know.
That's pretty definitive. It's clear she didn't tell him, AND because if she had, he'd have insisted on taking an oath she didn't want, which is why she didn't. How much clearer must they be, than him saying "Why didn't you tell me?" on the subject of a never before seen son, that he is surprised about, in the context of her never having wanted his involvement until now?
Returning to my initial point about Worf's parenting. I wasn't saying Worf is a derelict parent who ought to lose custody or something. I wasn't even saying he's a terrible parent, although he surely could've been better, even by nonhuman standards, & certainly by those
What I was saying, as it applies to this thread, is that Worf is ostensibly known as honorable. He never shuts up about it, & yet, nearly the whole time, he is actively, diligently even, dishonoring the wishes of his son's mother, that WE all know about. She told him she wanted the boy to find his own way, and that her being half human was in fact of value to her in his identity. Remember, he slaughtered a guy over the honor of revenge for his mate, but he can't show some thought towards her wishes?
All the time he ever spends with the kid, he shows no consideration to her wishes/values at all. It's all deliberately left out. If anything, he makes it even worse by pushing only his set of values on him, and then shipping him off to live among another set, which he has rebuked to some degree, sending the worst of mixed messages
And all I'm saying about that, is that an "Honorable" character spending a huge portion of his development being dishonorable, & it specifically never getting addressed, doesn't track very well imho, thus why I thought it made a good addition in here