https://www.reddit.com/r/DotA2/comments ... e_old_hud/
That is not going to happen, and there are technical reasons for that.
The only reason Valve updated the HUD UI (and the main menu UI) in the first place is because they have to get rid of ScaleForm.
ScaleForm is the old (and still partially used) UI library that Dota 2 has been using since the very beginning, but there are many problems with it.
One of the problems is the fact that Valve doesn't have access to the source code of it. There are countless ScaleForm issues that simply cannot be fixed by Valve. With the new Panorama framework developed by Valve themselves, they can fix any bugs they come across.
ScaleForm has been probably the biggest source of crashes ever in dota 2. It's immensely buggy, and causes insane amounts of crashes for people. From reading Valve's Os X / Linux bugtracker there must've been hundreds of reported Scaleform crashes that Valve couldn't fix.
ScaleForm was also the reason Vulkan wasn't really usable in Dota 2, because it has some Vulkan implementation bug that caused some issues with displaying ability cooldowns. And again, Valve couldn't fix it because it's closed-source.
Scaleform is still used in CM and some other mode i think, so they haven't gotten completely rid of it yet unfortunately. But this is the right direction. Valve simply can't bring the old ScaleForm mess back, and redoing the old UI in Panorama is going to be a massive amount of work.