In reply to Anuta.

This comment seems very dubious, and doesn't reflect the actual Gutenberg install/activation experience whatsoever. I have several early adopter clients using Gutenberg on staging sites (and one on a live site) with fair success, and have yet to restore a single backup. That being said, your comment seems unrealistic because it doesn't reflect how Gutenberg actually works.

Since Gutenberg contains page content in a classic editor block, it can't break pages when you click "activate". No major changes happen until you click "Convert to Blocks", and then those changes happen in draft mode giving you ample opportunity to review in HTML before updating. Perhaps the "instructor" or "host" hosed something, but it seems more likely that this account was fabricated entirely. There's no reason to be vague about a new CMS or the name of one's school if those entities actually exist.

Furthermore, no decent instructor would instruct a student to push a major feature update to WordPress to a live server. If you haven't learned to develop locally, push to staging and then swap to production, you're not in a WordPress development class; You're in a "Playing with WordPress" class.