Google Drive will now open Microsoft Office documents (.docx, .xlsx., .pptx, etc.) directly in editing mode. In the past, when you double-clicked on a Microsoft Office Document, the file opened in preview, giving you the option of switching to edit mode.
I could have sworn that I’ve been opening documents directly in edit more for some time. Maybe I had changed a setting somewhere. I’ve been known to do that and then promptly forget what I did.