
Agreed. That's kind of the whole point of the two main characters. MC doesn't show emotion because she's only ever received scorn and hatred from those around her. She's never once been loved and after being rejected and neglected by her fiancé for so long because she was too "clingy" she now holds herself back so that she won't be hated again.
As for the emperor, he keeps on a super polite mask all the time and keeps everyone at a distance after his previous fiancé killed herself. So he is also emotionless in a sense, because he is hiding whatever he feels behind a kind and polite demeanor.
Because if you contrast these two characters with Rudiger (the knight) who likes to tease everyone, the emperor's brother who is studious, affectionate, and clingy to his wife, the brother's wife who is strong-willed and headstrong, Rubiel who is take charge and stand up for herself despite being young... all these characters have distinct personalities and show their emotions more readily. I think it's actually well done how all of their strong personalities contrast with Neveah and the emperor's blandness, because it shows just how much of themselves those two are hiding.

It is similar though.
Neveah and Navier are originally in relationships that they are neglected and misunderstood (Sovieshu and Valer are just plain dumb and realize how much they care about the FLs after the women smarten up and leave). King Heinley and the Emperor Ardent/Joseph both are fantastic MLs in their own right.. each step in and do their best to comfort, support, and encourage their FLs.
This is like a ‘softer’ version of “The Remarried Empress”. My criticism would be that the characters have yet to come out more with their personalities cuz so far, everyone seems bland and it’s hard to get attached to them. Maybe a narrative problem? The plot is moving well though.