This would be helpful to me as well. I often have students join my (synchronous) class partway through the term. It would be nice to have a way to bulk excuse past assignments so those don't clog up the student todo list.
Yes, please! I've been waiting for this for years and have seen a few different people posting about it since then. Either checkboxes in the gradebook to select multiple assignments at once to edit and excuse, or a feature in the quick edit to do so.