I’ve seen a couple of other threads in which custom_components are beginning to give warnings that they need the directories to be restructured or they will soon fail.
It’s fairly easy enough to make the switch (unless you have a ton of them, I guess…) but when/where was this change announced?
the good news is you can switch to the new file structure now to beat the rush and your stuff will still work. the bad news is it also breaks the custom resource tracker card once you switch to the new folder structure unless the dev catches that change and updates their code. 
EDIT: I just re-read the post and saw this:
That’s a pretty nonchalant statement for something that could end up breaking a significant portion of peoples set ups in the near future.