Group chats are virtually essential to WhatsApp -- it's not uncommon for families or even community organizations to use it for staying in touch. To that end, WhatsApp is adding a string of features that help you keep abreast of group chats, whether you're running the show or one chatter among many. Administrators can set descriptions, rules and topics for groups, and determine who's allowed to change those settings (including the option to remove permissions from regular users). And no matter how much power you have, you can use a catch-up feature to check your mentions or search for participants from the group info page.
All of these features should be available in WhatsApp's Android and iOS clients as of today. They're clearly most useful for larger groups, but that's arguably the point. WhatsApp is aware that its chats sometimes serve as vital communication tools, and improved control over those conversations might just help someone in need.