I have experienced this on a cubieboard2, thus on armv7h.
As the title says, after systemd's update to version 233.75-2 systemd-resolved is automatically enabled. I've tried to figure out how it gets enabled but I haven't seen any obvious reason why it gets enabled.
I'm already using unbound for dns so I don't want systemd-resolved to be automatically enable on systemd's update, besides it is bad to enable services behind the user's back.