Square Enix announced some important content related to Final Fantasy XV on their official Japanese Twitter account.
One of them is the exact release date for the modding tool for FFXV PC version which was talked about some time ago.
Tool for this modding will be called as "Mod Organizer"
Mod Organizer for Final Fantasy XV: Windows Edition will be released on June 7, 2018.
No information related to size or how "in" this tool can offer existing mod content.
The Organize module will also arrive along with other update content, such as a new recipe for Ignis, options for cutscene skip in Chapter 3, and fixes some bugs.
Other content related to the release of DLC "The Party Pack" which contains cosmetic items for Comrade mode.
Final Fantasy XV: Pocket Edition for Windows 10 version will be released on June 6, 2018.