These changes will break the economy and the folks who will most suffer are ordinary players who just want to use the AH to buy cheap mats needed for their consumables. It will also really negatively impact folks who enjoy transmog, glyphs, or other cosmetics markets as maintaining those markets simply isn’t worthwhile with a broken in-game economy.
Cancel and reposting is frustrating certainly, but the net result it has typically is to drive down prices over time, and maintain an efficent economy. With these changes that will break down and the person who Blizzard claims to be helping will get completely screwed over.
Making this type of change with no communication is honestly such a shocking way to treat the playerbase, especially when the WoW economy is connected to the real world dollars and cents. This is a terrible change that Blizzard is making in lieu of actual investments in a core game system, and it should be reverted immediately.
In the future these changes need to be communicated in advance rather than made in secret.