Notion empty icon killer is a google chrome extension that just remove the default icon set by Notion when you have a page with a content but without an icon.
Since google want me to pay 5$ to register myself as an extension developer, I won't publish it because I don't know if someone else than me will use this extension. You still can use it for free by cloning the project and following this instructions.
I may someday publish it for real if I get 5$ from the community !