I emphatically support this idea.
Old method:
1. Upload contacts to existing static list.
2. Workflow is triggered.
New method:
First: Either add a Lifecycle Stage field to your upload, or update your workflow to set the Lifecycle Stage property. This was previously handled during the upload process.
1. Upload contacts.
2. From Imports screen, click More > New List.
3. Name your new list.
4. Wait ## minutes for new list to populate (time depends on list size).
5. Click checkbox to select all contacts in current view.
6. Click “Select all ### contacts” text link.
7. Click More > Add to Static List.
8. Workflow is triggered.
Sidenote:
Don’t bother clicking the “View Contacts” button on the Import screen. You can neither add all contacts to a static list nor create a new List from that screen. You can only add some contacts to a static list from there. The option to add to a static list is made unavailable after you select all contacts.