Dev team doesn't tell GM's anything?

So as it has been put out the HH mount can only be gotten from the epic boxes as the devs stated on their twitter, yet if you ask any gm regarding it (like if your not sure to run 40+ toons a day) you get a completely different answer. Why doesn't the dev team notify the employees who work directly with the customer of changes? What was the motive behind removing items from loot tables for low level characters and not saying anything until after the event began? This is in stark contrast to other holiday events (love rocket, brewfest ram/kodo) that were lowered in level, and loot tables didn't remove mounts for low level toons. My response from a gm:

Greetings *removed my real first name*,

Game Master ..... here to assist you today!

I see that you're wondering about the Headless Horseman mount, and what level is required to get it to drop. That's a good question for sure, so I went to check this out for you!

In the past, the minimum level required to obtain The Horseman's Reins (http://www.wowhead.com/item=37012/the-horsemans-reins) has changed due to changes in-game and feedback from players. This year is a little different than last, as we lowered the level required to obtain the mount. Anyone who is level 23 or above can queue up with the dungeon finder tool to get a chance at this mount. No more needing to be max level or near to it!

Side note on this is that if you create a demon hunter, they will not be able to enter any LFG groups until 24 hours after their creation, so while they are above level 23, they wouldn't be able to get a chance at the mount until a day after their creation.

Hopefully you're all set with this information - As always, my goal is to make sure you're completely taken care of. I wish you a great night with many epic adventures in your future!

I don't blame any GM for trying to help players with the information they are given, I've never had a bad experience with a GM either. But seriously? Developers not letting anyone know that they changed this after they announced months ago they were lowering the level requirement? I feel cheated, and somewhat lied to that they didn't feel it important to tell folks who spent or spend months leveling alts (dks in my case) for a rare mount that countless people persue each year.

TL:DR why is the dev team making changes and not telling players or the gm's for a 14 day once a year event?