I would be very surprised if they remove the fields from the database and the menu system because that would break upgraded sites from previous versions.

unbelievable decision from DNN to just remove a feature like this... hopefully the new DNN management will reconsider and truly listing to community voice like they claim?

I have built a form with the option to upload the icon file and then enter the Tab ID of the page you want to update the icon file for or add an icon file too. I will post a link to download it. I used Action Forms to do it but you should be able to do the same with other form modules out there like Live Form, Dynamic forms, etc.