I just got a reply from viki staff, where I was told that due to legal agreements with the content providers, they are not able to provide the licensing information such as the license expiration dates in advance.
I had asked worried about 4 older shows I'm working on.
Of course this will mean that less and less people will concern themselves with older shows. I know I won't be working on any older show after I finish these ones. I'd hate to see the license expire just after I'm finished or just before I'm finished. It's a major turn-off.