@Chris_Hofer unlike your experience, I was able to find the form in my LTI list of Google docs (accessed from the Rich Content Editor), but the icon was for a document and not a form. When I embedded, students viewing the page see a message "This content cannot be displayed in a frame" with a link to open it in a separate window. The form does open correctly in a new window using the link.
Clearly the form can be displayed in a Frame since the older "Send" and then copy the embed code for a form still works fine. Something is wrong with the security of displaying the form using this new method. Well the Canvas documentation does say "document, slide presentation, or spreadsheet" so I guess other types of files aren't included.
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.