Our plan is to release Jessie, but without systemd.

To make it clear that's what we are doing, what could be simpler
than to use the name Jessie for our version of Jessie.

Instead of me talking about Debian Jessie, I'd just talk about Devuan Jessie.

The most obvious difference will be that apt-sources mentions devuan
repositories where it now mentions debian repositories.

If we go our own way after that, we need not retain the same release
names.

-- hendrik