Warning! Spoilers for The Boys comic book series below
When The Boys comic book series originally published its initial six-issue run, it was actually under the DC Comics umbrella under the WildStorm imprint. However, after its first arc, The Boys was canceled for being too dark; as the series co-creator Garth Ennis once explained, the publisher was "too uneasy" about the "anti-superhero tone" of the comic. So while The Boys never crossed over with the DC Universe, it was at least possible at one point.
The Boys has become a pop culture phenomenon, largely thanks to the live-action adaptation airing on Prime Video based on the comic book series of the same name. However, years before the series was adapted on the small screen and even previously published by Dynamite Comics, it debuted under the WildStorm imprint founded by Jim Lee. DC Comics purchased the imprint in the late 90s, with several characters in the universe, including the Grifter, Midnighter, and Apollo. However, one creator-owned book DC canceled before it could ever potentially crossover into the DC universe was The Boys, with the reason being it was too dark for the imprint.
When The Boys was first published under the WildStorm imprint from DC Comics, it was swiftly canceled as, after just six issues, the publisher axed the series. However, co-creators Garth Ennis and Darick Robertson were able to keep the rights to the comic, eventually finding a new home for the edgy, dark series. It would run for 66 issues as part of the Dynamite Universe - plus another six issues as a miniseries. Ennis admitted in an interview that the reason for its cancelation from DC Comics was because of the anti-superhero tone of the book. In a statement, Ennis said it was a mistake the book was released under the publisher, saying it was "obvious to all concerned that The Boys should never have been published at DC."
The Boys getting canceled for being too dark and edgy by DC Comics benefited the comic's creators in hindsight. Under Dynamite Comics, The Boys could get even darker, which, for better or worse, it often did, while continuing to poke fun at DC Comics in even more obvious ways. The series had more creative freedom, pushing the envelope of its deprived stories and characters. Without its initial cancellation, there would be no The Boys television series or more than 70 total issues. It was more than a blessing in disguise, as The Boys' creators welcomed the chance to change publishers.
While it's a shame that The Boys never got to officially crossover with DC Comics before its abrupt cancelation as other WildStorm series have, it's for the best that never happened. The Boys relentlessly satirized the DC Universe, and if it had crossed over into that world, it would cheapen the jokes made at the publisher's expense. Instead, Dynamite Comics was the perfect landing spot for The Boys as opposed to DC Comics, as it would become a pop culture juggernaut years after its initial run, largely thanks to the publisher's belief in the series.