I thought I might share it here, if anyone is interested in participating in its development. There isn't a Flatpak version yet and it also misses some features e.g.
I have tagged this repository with the MIT license. From my understanding this means that the users are free to take the contents of the repo and try to encrypt it all and sell it to each other. Some day, maybe a user will download this repo and reprogram a modified version that only plays the DotA map and use that as a DotA engine thing that they would sell to others and prevent me from modifying or using their upgrades. In my opinion, that is not very cool -- and I do not have experience playing the DotA map -- but I am setting up the repo here so that it does not stop them from doing that. Also, I am guessing that since MIT license probably allows selling modified versions of the code and stuff, this hopefully would leave the door open that Blizzard could download this repo and take stuff out of it and include it in their private Warcraft III game code if they ever needed to. At the time of writing I do not think my repo has anything in particular that Warcraft III Reforged does not have, however, so this is purely hypothetical that I am intending to leave as an open door for the future.
By the time the developer wrote that passage he/she could have just read the MIT License as well as GitHub's auto-generated bullet points several times. 😄
If the author really wants Blizzard to use his code then he doesn't have much of a choice. Although since it has a GPL library the whole project is distributed under the GPL.
As the copyright owner you can do whatever you want. You can make your code gpl and give (written) permission to only blizzard to use the code under a different license.
You'd need a CLA for potential contributors though and I have no idea what courts think about it (not a lawyer, not legal advice).