Aspiring map makers may want to avoid Blizzard and World of Warcraft. The reason is that the company is claiming ownership of the community maps. After what happened with DOTA the company is not very happy with the inability to monetize the community content.
Legally the contribution is the work product of the person who made it. By confiscating those rights, there is the prospect for litigation should a repeat of what happened with DOTA may repeat itself.
An EULA was an unconscionable term or terms can be found to be unenforceable. In practice, EULA challenges in the US have rendered them almost worthless.
Has Blizzard approached the DOTA developer and worked with him the mess could have been avoided. Blizzard could have earned money as a publisher for the standalone game. Instead they lost it all.
As it stands now, Blizzard has alienated the community who are now flocking to other games.
Microsoft Games welcomed the community maps, which were very popular with the consoles, to the new Steam versions of the Master Chief Collection. One of the big reasons for Halo’s continued success is due to community support.
Many game publishers now welcome the community map makers. Valve has even gone as far as letting them use the game engines for new stand alone titles. CryEngine has also welcomed the community. Bethesda has also reached out to the community.