Warstories sort of became less common / popular some time back. There wasn't as many warstories posted in the forums as in the past now, and those that had the quality to be archived were even rarer. So yea, the Warstories Archive are now 'archived'. There hasn't been a warstory sent into the archives for a year now.
However, that isn't to say that warstories are completely dead now. It's definitely a lot less common, but you're still allowed to post them. There just currently isn't enough activity warstory wise to justify having an active archive I guess ?_? Perhaps if there is enough popularity / activity, the Warstories Archive might be brought back idk :O!
Sandshrewz summed up everything very nicely. Warstories are still allowed, it's just that no one seems to want to write them considering how rare a warstory worthy battle is and how time consuming warstories can be to create.