Hulk is one of those properties (like Spider-Man) that’s still entangled with other companies from before the MCU existed. Universal still has distribution rights to any solo Hulk movies, so while Disney could make another Hulk film, they’d be giving away a massive share of the profits. That’s why they’ve been sort of weaving the Hulk’s story and evolution through other character’s and ensemble films, and now the upcoming She-Hulk series.
I’ve got both issues of this Grand Design on my “to read” pile, and I just saw they’re releasing a treasury size compilation of both in a couple months. I should’ve just waited for that ‘cause I’m definitely going to get it!