In the last couple of days I've started work on the buster branch of Freedombone. "Buster" is the codename for Debian version 10. It's not officially released yet, but is expected to be within the next few months and by the time that happens there should be an equivalent Freedombone version. I expect that it will take a while to get fully working, but I already have an image which builds and a few apps which are confirmed as being installable. Email also appears to work with only a small fix to Dovecot settings. Searx search and the web interface also work.
Based on initial tests I think the upgrade from Debian 9 to 10 is going to be easier than it was from 8 to 9. It will still take quite a while to test the installs for each app, and sometimes different package versions need to be used.
Debian 10 brings PHP version 7.3, and that means that Pixelfed and some other new apps will be installable. It will also be able to support more single board computer models and TLS version 1.3 will arrive.
The future is looking quite good for self-hosting and the stability of the Debian GNU/Linux operating system makes it possible to run a server at home without constant maintenance.