I think they know that, they were asking when the classic one's were getting migrated to modern :).
But basically they are doing them as they see the need as far as usage goes. Not all of them may get done, but They are doing 3 more soon, just saw the post for them, Promoted links, and a few others. Still waiting on the tasks one, but that's not a big deal cause I just started setting up custom list for task lists. But at this point they are just plucking off a few here and there and just adding new ones to other systems.
Usually gets posted in the admin center message center. The promoted links got updated but it was the modern list UI not an actual web part update. The closest you can get is highlighted content web part.
The new image webpart updates coming may also be able to mimic the promoted links since we’ll be able to put text overlays on images soon.