Screen Options Missing - which makes it impossible to turn off Meta Boxes

[rickandersonaia]

Describe the bug The Classic Editor retains the original Screen Options tab which allows the user to turn off unwanted meta boxes.

To Reproduce Steps to reproduce the behavior:

1. Go to the post or page list screen, open with gutenberg
2. Screen Options don't exist

Expected behavior I expected to be be able to see the Screen Options tab and to be able to disable meta boxes

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Windows 10
• Browser Chrome
• Version 67

Additional context

• WP 4.9.8, Gutenberg 3.4.0

[youknowriad]

A decision was made to abandon these options because:

• A lot of people don't know about them (discoverability)
• Prefer Gutenberg extensibility APIs over metaboxes in plugins. (those plugins support pinning/unpinning)

More discussion here #5841

Thanks for the feedback