That's also my assumption as it makes a lot of sense, basically what they're saying is "wet" warm rice is a breeding ground for bacteria.

Though reading wiki for B. cereus it doesn't seem like an issue for "fresh" rice but rather when rice is cooked, improperly refrigerated (aka not refrigerated immediately), then just warmed over: this allows spores to germinate, grow and produce toxins which are difficult to destroy (wiki quotes 56C for 5mn to destroy enterotoxins but 121C for 90mn for emetic toxins).