WhatsApp new update to auto delete messages after 90 days
The header for the page is outdated and still shows 7 days, showing that the feature is still under development. It is likely to be corrected before WhatsApp releases the feature for a wider user base.
In personal chats, the option for disappearing messages can be toggled by both parties. In group conversations, anyone can change the setting, by the group administrator can select which members can, by going to Group Setting under Group Info.
It seems there will be some time before the feature is available for beta users. It then might take weeks, or even months, before arriving on normal users’ account. ReadMore
Source : techiyogiz