I think by adding read receipts to updates on a task or project level would be beneficial to Project Managers as well as others working within WF. It would allow the PM to see if their messages have been seen or read that way they can follow up when necessary.
Currently you don't really know if someone you assigned a task to or @mentioned in an update has seen your message unless they select work on (one of the biggest pain points for our team currently). Adding this feature would definitely help to alleviate that!
Thanks!