@Johnny
I understand what you mean when you say..
I disagree with a strategy that gives players the opportunity to plan out how to take advantage of a feature like combat being offline.
At the same time, that runs counter to the suggestions that we are all given to assume everyone is playing with the best intentions and not seeking to exploit the game.
If giving players heads up is going to lead to too many headaches for the staff due to bad apples ruining the bunch, do you have any suggestions for things like;
Character uses a bunch of disposable items (combat drugs, etc.) only to find out 5 minutes later that they cannot combat?
Group of characters coordinate schedules across multiple time zones to do (Thing) only to find out they cannot because (Planned event that staff knew about but decided to spring on the players without warning)
While I get your concern, it seems a bit overblown and runs contrary to what is otherwise a great change management program that is being run. You guys have a code repository. You have a dev environment. You probably do source code review and maybe even pull requests.
Change notification is just a basic part of change management.
It makes me a bit sad that there seems to be such a deeply rooted distrust of the player base that the initial response is… "If we do that, players are going to take advantage of it by breaking the rules and acting irresponsibly."