Essentially, they introduced a new post editor, as a plugin, which will eventually replace the old editor.
We're following the rest of the industry and calling these the block editor and the classic editor.
Thankfully, our themes to date have avoided touching elements of the post editor. This means, nothing has changed. All Feast themes are 100% block editor compatible.
All blocks (excluding some we're intentionally not supporting) display great in the themes:
Edit: you may notice some breakage on those demo displays - that's because the block editor is still a work in progress, and we don't consider it "production ready" - live sites should use it at their own risk.
What is the Block Editor?
It's a way to create and edit posts, that does exactly the same thing as the original, classic post editor. You can create the exact same posts in the classic editor as the block editor.
What the WordPress core team is really trying to do is create a page builder with the block editor, in response to other page builders that have gained traction (eg. beaverbuilder, elementor, divi).
This is actually a pretty dirty move because it puts WordPress in competition with it's own community (pagebuilder plugins), but that's the decision they've made.
Block Editor Support + Troubleshooting
The themes behave exactly the same in the block editor as they do in the classic editor, which is: we don't touch it. This is how the themes were always designed.
The block editor plugin is not a product developed by Feast, and therefore doesn't fall under Feast's support domain. It's WordPress/Automattic's job to provide support for their plugin.
However, there's a zero percent chance that the average blogger will get help from the WordPress core team, which is the only reason we don't recommend using it.
We will eventually be developing functionality to enhance the block editing experience. However, themes are designed for styling, not functionality. All functionality belongs in plugins, and any new functionality we develop will go into the Feast Plugin, where it belongs.
For more information about styling vs. functionality, see: https://feastdesignco.com/what-am-i-paying-for/
This is to avoid the mistakes themes with "built in functionality" have made in the past - like themes that claimed to offer "recipe plugins" which were terrible, bloated, and never got updated.
Do you recommend using the block editor?
Anyone is free to use the block editor, if they're willing to take the risk of things breaking, and not receiving support from the developer.
Our recommendation, as soon as you update to WordPress 5.0, is to head to Plugins > Add New > Classic Editor > Install
Long-term, we believe it will be a better experience for WordPress users. Short term however, they've introduced a technical mess for plugin and theme developers to respond to, and have not positioned it properly. When the block editor was finally released, that's when developers could finally begin updating their plugins to be compatible, not WordPress end-users (the bloggers).
Even this is questionable - the block editor is still changing. We're not touching it until mid-2019 because it would be a waste of time to have to re-code everything while it's still changing. We'll let other people be the guinea pigs and break their own sites.
Bloggers (you, the reader) should wait until more developers have announced support for it.
Are Feast Design Co.'s themes compatible with the Block Editor?
A theme's role is to provide styling for the front-end of your blog, and it works perfectly. See this post for more information.
Theme versions greater than 4.0 fulfill the role of a theme perfectly with WordPress 5.0+ and Genesis 3.0+.
Theme versions older than 4.0 probably need to be updated.
Will you provide support for the block editor?
Our themes were never designed to change the post editing experience, and will not be changing.
If you have issues with the block editor, you'll have to get support from the WordPress core team, and they won't bother helping you.
Most important: make sure your host has a daily backup. If your blog crashes or is unresponsive, your best move is to restore your previous working version and not do that update until you're told it's safe.
Simply do not use the block editor unless you've hired a developer personally to handle your blog, or you're okay risking breaking your site and not being able to find a developer to fix it for you. The block editor does nothing the classic editor can't do, and comes with risks.
As always, we recommend you're on a premium host like Agathon, Cloudways or BigScoots, who does automatic daily backups so that you can restore yesterday's version if you break something.