Hey @JammyDodger.
TLDR
I think that somene should add a link to this announcement somewhere very near the top of the admin guide.
Here’s why
I’m setting up a new site and think that the new “getting started” button is much nicer than the more cryptic “you are in bootstrap mode” we used to have.
But I don’t know how a new admin would have any idea that Getting Started is in any way connected to bootstrap mode. It’s also not entirely clear that this button is visible only to admins (unless you stop, think, and then trust that the designers wouldn’t show /everyone/ a button that applies only to admins).
The references to bootstrap mode in the Getting Started Guide are pretty far down and don’t explicitly say that they are related to the Getting Started button. I suspect that many more people are confused by this message than is evidenced by the very small number of messages about it.