Groupified Team sites do not allow a site design to set the site logo. Apparently the Office 365 Group logo needs to be changed but this requires considerable code or manual steps for each group created. Since many Office 365 groups will be created via Teams or SharePoint Online its somewhat obvious to allow organisations to control the user experience via basic scripted branding and site designs. Please allow the setSiteLogo verb to also update the Office 365 group logo and have it propagate immediately through to Teams and the SharePoint Online team site.