During your SharePoint Online migration, you may want to enter the TemplateName in the CSV list.
Coming from this source, you will find below the list of the different “modern” templates (TemplateName or “Template ID”):
|Template ID / Template Name
|Description / Additional Info
|A site with no connection to an Office 365 Group.
|Publish dynamic, beautiful content to people in your organization to keep them informed and engaged on topics, events, or projects.
|For Reporting Only – You cannot create sites with this template
|For Reporting Only – Delve Blogs are being Retired
|For Reporting Only – Use the Request-SPOPersonalSite cmdlet to pre-provision a OneDrive for Business ite
|Placeholder template for the old URL when you rename the Site URL. This is for reporting only and those sites are only created by Microsoft programmatically.
|Lightweight Site Collection provisioned for each Teams Private Channel Site. This is For Reporting Only, and not for manual provisioning trough SharePoint Online.