Hi @PeggyR
This sounds like a variation of the problem that we have when importing content between Canvas courses a) everything is published and b) it is published to 'Everyone' rather than specific sections. I'm hoping this may make it onto the Roadmap as a tidying up issue.
There is an idea for bulk edit of announcements currently in Ideas and Themes.
I'm not a programmer (and our IT team wouldn't allow local scripts anyway) so couldn't deploy @jerry_nguyen's pragmatic solution.
Bulk upload from alternative LMS's and between Canvas courses really does needs to reflect the needs of the larger number of naive users who need a Turnkey/Plug and Play Canvas environment.