Change record status: 
Project: 
Introduced in branch: 
8.0.x
Introduced in version: 
8.0.0-BETA8
Description: 

The page template still has a hard-coded messages variable. That is vestigial and hard to remove and defeats the whole purpose of making messages a block instead.

The messages variable has been removed from the page template entirely in the template_preprocess_page() function and page.html.twig template. Now, a default block places the messages block in the same place.

A default 'messages' region has been added. All themes will inherit it unless it specifies different regions in its .info.yml file.

Impacts: 
Site builders, administrators, editors
Module developers
Themers