It is now.
She's listed as deceased because Gin said he killed her. Whether this is a lie or not we don't know yet, but as of know, the confirmed fact by Ichimaru is that he killed Rangiku, and that her reiatsu couldn't be sensed, even by Aizen. Until we have a proof that she's not dead, she'll remain "deceased".
She has been shown to be alive and the wiki has been updated to reflect that.