For group chat, this makes sense. For email, not so much.
Most of the modern email clients come equipped with some kind of snooze functionality that does the job of triaging. Most of the times, it’s easy to ‘Do, Defer (Snooze) or Delegate’, just by looking at the sender of the email and the subject, without reading the content of the email. Gives you a fair amount of context and is a super-fast way of getting to Inbox Zero.
I like the ‘Hey’ menu, but isn’t it just a contextually well-designed email inbox?