The new Gutenberg editor will be the default in the coming WordPress 5.0. However, a plugin will allow users to use the classic editor, if they want.
I’ve been using the Gutenberg editor and a Gutenberg-compatible theme on this blog for a few weeks now. Yes, things are different and there is a bit of a learning curve. It’s worth it. The Gutenberg editor is hugely better and way more powerful. Everything is drag and drop. Things that were hard to do in Classic editor are now easy.
Gutenberg-compatible themes do everything in Customizer. There are not as many options for tweaking a theme as there were in, say, Canvas. This will be missed. However the themes do have an area for custom css.
WordPress is working hard to make the transition easy. However, change is coming. Plan and get ready for it now.
“WordPress 5.0 is likely to land in the coming months. This has people wondering how best to prepare, and we certainly understand why. You can rest easy knowing these options and features are available:
Firstly, your existing pages and posts will be converted to Gutenberg using the “Classic” block. This allows them to exist and display just as they do today without any manual intervention.
Second, if you edit an existing page or post and anything unexpected happens, you can easily restore using a plugin.
Third, if you simply prefer the legacy editing experience, you can download the Classic Editor plugin to revert back to the editor you want.”