It wouldn't surprise me if Cannibal did open this weekend. The temporary scaffolding that was above the tower exit has been taken down, everything that was in the station like tools, tables, chairs, etc. that aren't necessary for the ride have been taken out. When Lagoon opened Wicked, they didn't say anything about it. That is most likely how they're doing it again.
Lagoonisfun.com is a very trustworthy site with a lot of information on Cannibal. If you need anymore info on Cannibal I recommend going over there.