Bizarro Episode: The Gen 13 ABC arc featured cameos by everyone from Wolverine to Spawn to Archie to Bone to the Teenage Mutant Ninja Turtles (the latter of whom are getting sick of their overwhelming success and popularity and would like to go back to just being independent comic book characters).
Ensemble Dark Horse: The DV8, as of their mini-series, Gods and Monsters. The series has been almost universally praised, and is a big step up from their former role as Psycho Rangers to the Gen¹³, giving them all decent characterizations, beyond that of "sociopath/monster".
Replacement Scrappy: The Claremont-era team were hated before they even premiered due to Wildstorm ordering the original team to be killed off to make room for them. Once the team made its debut, they were hated even more for being a bunch of ethnic stereotypes.
The original series featured a lot of gratuitous fanservice involving Caitlin, Roxy, and Sarah, despite all three of them being teenagers. This didn't get much attention back in the 90's, particularly since the series was outside of the Big Two comic companies, but it's probably highly unlikely that someone could get away with something like the Janet Jackson parody cover (featuring a topless Fairchild being groped from behind by Grunge) nowadays.
Even though Fairchild was stated to be 18, the other 2 were implied to be underage, which makes those scenes with them much worse.
The original series' handling of Rainmaker's sexuality left a lot to be desired. Despite being explicitly lesbian, she was never given a female love interest, but was instead given at least two male love interests, and frequently subjected to Male Gaze. Eventually Scott Lobdell retconned her as being bisexual so that he could pair her with Burnout. When Gail Simone rebooted the series, among the changes she made was making Sarah explicitly lesbian and erasing her prior relationships with guys.
The rebooted series by Gail Simone introduces Burnout sporting dreadlocks, which get shaved off in the second issue as a form of personalized "torture." The others all feel bad for him, but if Bobby tried something like that today he'd be accused of cultural appropriation as a white guy wearing a Black hairstyle. Even when later issues explained Bobby adopted this hairstyle because he was fond of music by Bob Marley thanks to a Black social worker he had sessions with, said social worker would most likely think it was incredibly offensive seeing him style his hair like that.