It turns out that you have to delete YourProject/Saved/Config/WindowsEditor/Engine.ini in order for your project-level TemplateMapInfos to be recognized.
Try that if your template map isnāt showing up in the āNew Levelā window.
In UE5, thereās a new way to do this now.
In Project Settings->Project->Maps & Modes, thereās a
āEditor Template Map Overridesā where you can edit an array of possible map templates.
Comment from the config field:
/** Map templates that should show up in the new level dialog. This will completely override the default maps chosen by the default editor */
Edit that array to point to your map templates, save, restart editor, and youāre good to go.