Update: It seems posting a new message on the list, gets rid of the status, so once changed, it goes away.
I exported the mbox of a list, in order to test how duplicates are handled. The total size of the mbox (uncompressed) is 20kb. On submitting it from the import tab from settings, the status of the import is shown.
However, the status is still showing as in progress even after some 10's of minutes have passed.