what the f*ck.. is doing blizzard...?
For those of us that followed this game closely, we are told the company ran out of money to fund this project. People like you will buy it anyway, so if you think about it, management is correct not to prioritize custom campaigns.
In the time since custom campaigns were gone, Blizzard released the Shadowlands World of Warcraft expansion, developed the game Diablo 2 Resurrected, and then sold the mobile game Diablo Immortal which raised $100 million in the first couple of weeks.
If you question their decision making, then you should look at the financials. These products and services are still selling and taking in all kinds of money. Having nobody work on Warcraft 3 much does not really cost this company anything.
Since you seem to be out of the loop, please be informed that on August 17th a new patch will overwrite your Warcraft III Reforged installation with a new game version. This new incoming version uses a new model format, so any modding tools you download today to edit Reforged models and assets will no longer work starting August 17th when you will be doing the next forced upgrade. In addition, any HD Reforged style custom 3D graphics that include custom particle spell effects (PKB extension files in World Editor) will cease to function after the upcoming August 17th patch. Other portions of the game will also break, such as how "Advanced -> Gameplay Constants" menu in the World Editor may no longer be able to edit Damage Table % values after the new patch.
So, after 2 years of relative stability because the Reforged developers were laid off, it is entirely possible that a new team of people unfamiliar with the code will be breaking even more features and systems in the coming days -- beyond those features and systems that I mentioned above. My information honestly might be out of date regarding what will and will not break on August 17th, because Blizzard took the patch testing private after the first few weeks instead of continuing with a Public Test Realm that was live for players like you and me.
By and large, it does not really matter who works on Warcraft III. The custom modding scene is too complicated and outside the scope of what Blizzard can financially support, so I do not think I am being unreasonable if I extrapolate and tell you that in 5-10 years Blizzard will probably drop support for more of the custom modding of Reforged in order to cut costs -- moreso than just Custom Campaigns.