https://www.pcgamer.com/it-sounds-like-monster-hunter-world-pc-wont-have-mod-support-at-launch/

Monster Hunter: World is coming to PC next month but seems unlikely to ship with mod support, according to producer Ryozo Tsujimoto. 

When asked if the game's Steam variation will come with mods, Tsujimoto tells us: "We don’t have anything to announce at this time."