Yeah, there are a few series that have been featured more than once. Lately they've been going through their Tapas-app exclusive series again so I think they're just waiting to get some more banners in (either that or they're busy and just haven't had a chance to refresh it with something new). Hell, I've seen "Down the Upward Spiral" featured like, 20+ times already (seems like it goes up every time they're about to switch the banner, it's only ever up for a few hours... anyone else experience something like this?) It's kinda been bugging me IMO because I'd like to be able to see some new series up on the banner that don't require coins and keys to read. I mean, I get it, Tapastic is trying to promote their app, which is all well and good, but it almost feels like the standard creators who aren't a part of the program are running out of options for promotion in favor of these "premium" series. I mean, they already have tons of promotion space on the app, can we at the very least have the banner space on the desktop site? Eh. That's just me. I'm done rambling lol They can do what they want.
TL ; DR: This isn't the first time Tapastic has reused their old features, it happens. I noticed the "Just in time for the Halloween season" thing too though, got a good chuckle out of it xD