He is moving on, that was quite literally the entire point of the chapter.
It's impossible to sympathize correctly because you haven't been through a war, your sibling wasn't literally the only person in your life who was a symbol of stability in a cutthroat, war-torn country. You never studied your ass off to live up to your sisters image of stability graduated at the age of 14 and then immediately plopped into a world of espionage and uncertainty.
I really hate how people keep taking spy x family chapters through surface value only. The author is conveying deeper meanings and themes through each tiny detail, and it'd do everyone good if we all just took a step back and tried to understand the depth of Yuri instead of automatically criticizing him and making 0 effort to realize why the author made him in such an image.
All of that can happen without Yuri falling head over heels for Yor btw, siscon is weird. It's not because we haven't gone through war but because incest is literally weird as hell and its hard to sympathize over a character with romantic feelings for their own sister. Ofc people wont try to understand Yuri when majority of his screentime is gooning over his sister. Why would you want to sympathize with that type of character
I could never sympathize with Yuri and his siscon complexity bc my brother never interacted with me even tho we used to live in the same roof for 13 years, still I mean living in war while only having your sister as your only companion is so heartbreaking. He still hasn't over come his dependability on his sister I hope he moves on too