In reply to George.

I'm certain "try" would have resulted in a lot of "fail" for many of the sites my agency runs, because meta boxes and other custom field customisations are critical. Clients would have been drawn to the new shiny and been quite upset when it didn't plan out as expected.

So I'm very grateful that Matt and the core team have listened to feedback. I was a Gutenberg sceptic but the Ship of Thesus post I read recently convinced me that this it is the way forward - it just needs to be carefully rolled out once it's really solid. One of the main reasons our clients love using WordPress is the ease of adding and editing content. Anything that changes that process needs kid gloves.