Warcraft 3 mods were something everyone loved and they even spawned new game genres but that is most likely not going to be the case for Warcraft 3 Reforged, courtesy of Terms of Service that immediately give Blizzard the rights to everything.
Blizzard's crown jewel turned into a crown of thorns as Warcraft 3 Reforged got downgraded and now players are asking for refunds. To make the matters worse, one of the most iconic features the original Warcraft 3 had will not be able to flourish with Reforged, or at least not as much as in the original.
This refers to the User Map Settings (UMS) which allowed players to create custom maps and change rules, resulting in new game modes. Others simply called them mods. These mods resulted in highly engaging game modes such as Footmen Frenzy, Line Tower Wars and Defense of the Ancients.
Footmen Frenzy could loosely be seen as a rudimentary version of battle royale but Line Tower Wars and Defense of the Ancients outright spawned new genres - tower defence and MOBA.
Players were looking forward to creating content like that in Warcraft 3 Reforged as well but then Blizzard hit them with Terms of Service that were discouraging, to put it mildly.
ToS' exact wording is "To the extent you are prohibited from transferring or assigning your moral rights to Blizzard by applicable laws, to the utmost extent legally permitted, you waive any moral rights or similar rights you may have in all such Custom Games, without any remuneration".
In laymen's terms - any moral rights to custom content you create in Warcraft 3 Reforged will be assigned to Blizzard and by playing the game you waive your rights to have them. Considering what moral rights are, it means that Blizzard can take your custom game, make it into their own and by doing so they don't owe you any money or credit.
League of Legends is probably the best example why this is so wrong. It is the most popular esport on the planet and is raking in obscene amounts of money each year, and it's a MOBA that wouldn't exist without Defense of the Ancients becoming popular. If the ToS was the same back when Guinsoo and IceFrog worked on the mod, Blizzard could take it and make it into their own IP. Neither of those two would get any credit for their work, let alone compensation.