In reply to Greg Schoppe.

Greg, if I may ask, since I'm in a similar situation as yours, what are your thoughts concerning the following potential problem:
Using “Classic Editor Addon” and “Classic Editor” we will be able to stop Gutenberg from being installed and causing problems with existing custom made themes and plugins. However, most sites use one or more plugins. Those plugins get updated to work with Gutenberg. For example WooCommerce is working hard to get it ready for Gutenberg. But I wonder if this could cause conflicts if “Classic Editor Addon” and “Classic Editor” block Gutenberg.

So even if I block everything related to Gutenberg on my clients' sites, there still might be problems. I cannot NOT update any plugin, since some of these updates might be security related. And once Gutenberg has been out for a while, more and more plugins will switch to using it (if applicable).