Thanks to Variety:
"Upcoming Nu Image / Millennium movies “Expendables 4” and “Security” are headed for China. That follows deals with Steven Paul’s SP International Pictures on behalf of SSXH Beijing and Max Screen Film Distribution.
The deals cover equity investments in both films and provide Chinese distribution rights. Both movies may use China as a location for some scenes, though it is not expected that there will be enough Chinese elements for them to be considered as full co-productions.
“Expendables 4” will shoot in 2016 and be delivered in 2017. Neither director nor cast have yet been announced, though the picture is expected to have maintain its all-action star formula. It is to be produced on a budget of over $100 million.
The “Expendables” franchise films have proved some of the most successful independent pictures in the Chinese market. “Expendables 3” grossed $39.2 million in North America where it was handled by Lions Gate Films, but $78 million in China.
“What seems to work in their favour in China, is that these movies are good old-fashioned shoot ’em up entertainment,” Paul told Variety."
Don't forget that in the aftermath of EX3 Stallone himself said that going the PG13 route was a big mistake and that the next movie would be R rated. Also it seems that this time they'll try to target the Chinese audience as much as possible, how about having Donnie Yen as a villain vs Jet Li? Let the speculation begin.