Ever since the current Ultimate Universe launched back at the end of 2023, there has been a countdown, of sorts, to a specific point in time. You see, the Ultimate Universe was manipulated by the villainous Maker (an alternate reality Reed Richards), and upon discovering what the Maker had done to his world, Howard Stark (Tony Stark's dad) successfully trapped the Maker in time for two years. All Tony could hope for was to get together enough superheroes in those two years that they might have a CHANCE to stand up to the Maker when he emerged from the time trap Tony's father laid for him. Well, those two years will be up soon, and Marvel has announced that that two-year countdown will also serve as the conclusion of Jonathan Hickman and Marco Checchetto's acclaimed run on Ultimate Spider-Man, the most popular book in the Ultimate line of comics.
The return of the Maker will be handled in Ultimate Endgame, by Deniz Camp and Jonas Scharf, which will launch in December, but coinciding with that event will be the 24th and final issue of Ultimate Spider-Man, which famously has taken place one month at a time for the 24 months that the Maker remains in his time prison.

Related
Miles Morales Leads a Tour of the Ultimate Universe in Ultimate Spider-Man: Incursion #2
In a CBR review of Ultimate Spider-Man: Incursion #2, see how Miles trip to the Ultimate Universe has expanded the world of the heroes there
What did Jonathan Hickman have to say about the end of his Ultimate Spider-Man run?

At Comic-Con International at San Diego (SDCC), there was an Ultimate Universe panel, and Marvel later quoted the panelists for a press release, including Jonathan Hickman noting, “This was everything that I pitched. Nothing has deviated. It’s been really nice to execute the plan well and everything culminates into this issue. Fans of the Ultimate Universe are going to love it. It’s been a real pleasure being the writer of ULTIMATE SPIDER-MAN.”
Marvel teased the final issue as, "Fans should prepare themselves for a startling finale that will cement the run as one of the most beloved Spider-Man runs in recent history. Packed with dramatic—and shocking—developments for the entire Parker family—Peter, Mary Jane, Richard, May and Uncle Ben—along with Harry Osborn, Gwen Stacy and more, the issue will also create promising roadmaps for future storytelling." That certainly suggests that a new creative team could be launching a NEW Ultimate Spider-Man series post-Endgame.
Speaking of Endgame...

Related
Peter Parker Deals With the Dangers of His Son Being Spider-Man, Too, in Ultimate Spider-Man #18
In a CBR review of Ultimate Spider-Man #18, see how Peter Parker's son being a superhero creates a very dangerous situation
What do Deniz Camp and Jonathan Hickman have to say about Ultimate Endgame?
Ever since Marvel started to tease the return of the Maker being its own miniseries event, fans have wondered who will be the creative team on it, and it turns out that Ultimates writer, Deniz Cap, will get the nod. Marvel quoted Camp as stating, "This is the craziest and most impactful crossover [I've worked on]. I’m really excited about it. It’s all the characters: everyone coming together in this big way, coming up against each other in a big way, and the resolution of some long plot threads we’ve all been seeing. It’s very big, very dramatic, and with the Ultimate Universe, we can change the world. We can actually do it as creators because we have this incredible playground that Marvel has not just allowed, but encouraged us, to use. It’s such an honor to do something like this. It’s been amazing, and this is the culmination of a lot of what we’ve been doing together.”
Hickman added, "Doing this tight continuity stuff, this smaller line… the execution from the company on this has been great, and it’s stuff we should keep trying to do. You guys supporting this book is the only reason we can [tell stories] this way. Hearing you like this gives us the opportunity to do more things like this."
Ultimate Spider-Man #24 will be out on Christmas Eve, while Ultimate Endgame #1 will follow a week later.
Source: Marvel