Taking permissions away is bad
"However, this soon caused problems, as this permission is also used by legitimate apps, such as Facebook, which requires it for its Messenger chat heads feature. Since most users won’t be able to approve the permission manually, such apps could be hurt by it."
I'm sorry but I fail to see the loss here. Here's a thought. If it was impacted they could update their app so it can see if the permission is granted and if it isn't then it points the user to a page where they can read how to give it permission. Instead we've got one door wide open for a few apps that were abusing the feature to begin with.
As someone that uses Google stuff a lot I'm amazed at how short-sighted this 'solution' is to the problem. I'm annoyed that they are seemingly fine with this being left alone until the next version. I couldn't care less if this wiped Facebore off the face of the planet but clearly a bunch of people having to pull down a notification shade to chat is more problematic than a gaping hole in your OS.
I have a solution. Tell Facebore et al to go die in a hole, release patches where possible and promptly give access to documentation on permissions and what they mean. I've thought for a long time now that every app should clearly explain why it needs each permission before you grant it access at install time. Those who get caught by bad malware and scams will ignore it and click accept as they always do (and suffer for it) but everyone else gets to see what they are allowing apps to do. I'd also make it clear that any app update must come with a changelog and not just "Bug fixes and performance improvements".