Following on from thoughts about the WordPress block editor and wondering whether the classic editor might be removed any time soon I found a reassuring quote from Matt Mullenweg that the plugin would be supported for many years to come.
Still, you know how these things go.
Somewhat interestingly, I also found reference to "ClassicPress" - a fork of WordPress BB, before blocks. It's based off WordPress 4.9 but, in future, intends to take a different path.
Curious, I performed a manual install, spun up a new database and copied my theme (and necessary plugins) over and created a test site.
JetPack doesn't work (or at least the current version) so I'm using a different plugin for Markdown support which seems to work okay despite being no longer supported.
I'm not sure I'd consider switching over until the platform is a bit more mature and demonstrates some longevity as there is no guarantee that it will survive long-term, despite any reassurances that the founders are in it for the long haul, but it will be fun to keep an eye on.
It may also serve as a dev playground where I can make changes without fear of killing the main blog.