I mean it’s kinda relevant to the story that the ML dad is getting out of prison and he is busy preparing for it more than drama it’s just a misunderstanding
It's not unnecessary tbh, it's about time the matter with his family got brought up. We only got glimpses of it in the previous season and it would feel very much unresolved to leave it like that. Siwoon also deserves to have a closure with whatever's going on with his family
why add unnecessary drama