The producer of Monster Hunter: World, Ryozo Tsujimoto, spoke in an interview about mod support and the possibilities of a cross-platform feature between PC and consoles.
With the planned launch on August 9, 2018, MHW will be the first main game in the Monster Hunter series to get a PC release. The extra time was to be used by the development team to make the port as thorough and tidy as possible.

However, modding fans and players who expected cross-platform functionality for multiplayer will likely be disappointed.
No cross-play planned
According to producer Tsujimoto, the development team has no plans for a cross-play feature between the PC version and individual consoles. Console fans will have to purchase the game again for PC if they want to play with their friends on PC.
However, the development team will try to release both balance and content patches as synchronously as possible. In particular, the overarching bug fixes are intended to be released simultaneously across all platforms.
Mod enthusiasts will have to wait
Native support for modding in Monster Hunter: World will likely not be available either. Producer Tsujimoto stated that he has no information regarding the use of mods at this time.

On Reddit, there has been speculation since the announcement of a PC version in January about which mods could be interesting or useful for MHW. Keywords like DPS meter and texture mods were mentioned, but these will likely have to wait for now.
It is unknown whether mod support will be available at some point in the future.
Here you can watch the first trailer for the PC version of Monster Hunter: World:
Watch the first trailer for the PC version of Monster Hunter World here!