Hi @CynthiaEdwards1 ...
That's a great question. I looked at the Studio "Settings" >> "Groups" tab interface, and I don't see anywhere that would let Canvas admins upload a batch list of names. Further, I looked at this Guide:
How do I create custom sharing groups in my Canvas... - Instructure Community (canvaslms.com)
...but I don't see anything here, either, that would indicate this is possible. 😥
This would be a great idea to submit to the Community, however. Here are some links for you:
Canvas Ideas and Themes - Instructure Community (canvaslms.com)
Once on this page, click on the blue "View and Submit Ideas" button. Then, on the next page, click on the blue "Submit an Idea" button. You should also look through the "Ideas and Themes" section within this link:
Instructure Community Guide - Instructure Community (canvaslms.com)
I would support your Idea if you submitted it here in the Community! Hope this helps a bit!