This is the first I'm seeing it's being considered they are taking away the option for players to remove the settlement systems. All previous education was to turn the settlements system to false in the config files. When did this change?
We help run a eco community server and almost all the patrons hate the settlement system so we have it set to false - as that's what it was instructed by multiple SLG staff. However, it sounds like this may no longer be an option for any of our future runs based on how your post is written?
Nothing has changed, the setting was a legacy setting from the beginning and as such may go away at any time. For dedicated servers that is barely a problem, as aside of few long-term servers there is no expectation of a save still working a year later, as such turning off settlements to save a bit of setup time isn't a big problem. We've been giving this information to players using local servers from the beginning and the settlement system can also purposefully not be turned off at game creation ingame, only via file modification.
There is no need to use settlements off in any case, servers can use the mentioned settings to enable unrestricted claims as before since a few weeks after release and a global government can be created quickly by two configuration changes and a few admin actions as well.
The legacy option is based on outdated code and no longer maintained, it is possible new civic features won't work with it.