The Hulk has been a main player in the MCU for years, but we've never seen him in a solo project since 2008's The Incredible Hulk which then starred Edward Norton (although it's still MCU canon). Now, it looks like we will get to see him star in his own solo film again soon.
According to The GWW, Marvel Studios is currently developing a World War Hulk film that is set to start production in late 2022. It will reportedly follow the events of She-Hulk. The film will be inspired by the popular comic book storyline, but it won't be a full-blown adaptation. The report also indicated that Marvel Studios has regained the rights from Universal Pictures which is why they are able to develop a new solo Hulk film.
The project has not been officially announced by the studio or reported by the major trades so we have to take this news with a grain of salt. There's also no confirmation if it's true that Marvel Studios has regained the rights of doing a solo Hulk project so the likelihood of this project being in active development is still 50/50 at best.
If the report is true at all, it is good news for MCU fans who have been clamoring for the Hulk to start in his own project for a long time now. We might have seen him star on his own in The Incredible Hulk back in 2008, but we've never seen Mark Ruffalo play the Hulk in a solo project. We know that there's still a lot to explore with the character and this will be an opportunity for him to shine on his own.
As for World War Hulk as possible source material for the solo project, it is an interesting choice. It won't be definitely a direct adaptation of the comic book storyline, but perhaps they might deal with the concept of Hulk looking for revenge. The Illuminati also hasn't appeared in the MCU yet so another group or individual might be the reason why the Hulk wants to take his revenge. There's a lot of possibilities and we will find out soon if this project is actually in development.