Because the chibi one(s) we've seen may not be official Takara product, and even if made by Takara, that doesn't mean they will/can be released.
Having said that, i think you guys are right. Based on the design and engineering, those look like an official product, and will be released as an MP. But with a chibi MP Cliffjumper being my most anticipated MP, i just don't want to put my hopes up only for it to be dashed.