We send a lot of emails to our donor list and this feature helped quickly take out all email entries, showing any contact or transactions. This helps distinguish those who are active constituents from those who are simply subscribed to our email list.
I think I am understanding you as being on a specific account donor's journal page and you want to be able to select all/none on the new filter. This is part of the SKY UI and i will pass this along to them for consideration of adding to the new filter.