This article explains how native Google Drive files are migrated.
During a migration from a Google Drive to another system (OneDrive or SharePoint Online), native Google Drive files are converted to Microsoft Office documents. The following table shows how they’re matched up:
|Native Google Documents||Microsoft Office Documents|
|Google Forms||Not migrated (ignored during migration)|
|Google My Maps||Not migrated (ignored during migration)|
|Google Apps Scripts||Not migrated (ignored during the migration)|
E.g. We migrate a google native document of type Drawing to a PNG document in Office 365 because conversion is not supported. Here is the response from Google API:
During migration from one Google Drive to another, native Google Documents are migrated as native Google Documents.