Messages disappear from header view before they are rendered

(Message on mailing list which triggered this bug report : https://groups.google.com/d/msg/mu-discuss/e0HtrPqvNjE/7LAxl6F1AAAJ)

This is the current situation (taken from above thread) :

When you open an unread message, it's marked as read, then opened again (with the updated status). If you C-g in between, then the old message has already been removed but the new one is not there yet. Delays can happen when the mu server is doing something else when you try to render the message.

For my own use case, if there's a way to mark the message as read upon exiting the message view buffer, that'd be lovely.