It kind of makes sense. For starters it's much shorter than a normal season so isn't a huge commitment to the 9 schedule. They have a Big Brother house sitting there which was probably being kept until a decision on thes hows future was made, so could easily be used to fill up 4-6 weeks at the later part of the year when there isn't much else on. It's also not committing to a full length season of the show and is giving something a bit differen to the usual season.
Plus Celebrity Big Brother in the UK is AMAZING. All you need to do is get a couple of whacky former UK celebs on the show and you have a winner. I know Australian casting is generally more safe so we don't have that level of controversy, but if 9 can have it in an 8.30pm+ slot like last year then I think it opens up to allowing a bit more riskier casting. Cast some former washed up international celebs and you have a hit.
Katie Price is rumoured to have already been offered to appeared. She won the most recent UK season. If she's on there it shocks me as she might have won but she was one of the most boring housemates that season. She won on celeb status alone and she means nothing to Australia. Plus her pay packet to get on the UK version was pretty extreme.