Stinger was released as part of the 'Ant-Man and The Wasp Character and Level Pack' DLC on the 3rd of July 2018 which added various Ant-Man related characters from both the original comics and the Marvel Cinematic Universe films. In addition to Stinger, these including Ant-Man (Scott Lang), Wasp (Hope van Dyne and Ghost as they appeared in the Ant-Man and The Wasp movie, Egghead, Crossfire, Giant-Man (Raz Malhotra) from the comics, and for some reason The Human Fly.
Before anyone points it out, I did notice that that the Stinger costume depicted shares the same silver doodad's on the shoulder pads as the Cassie Lang of the Main Marvel Universe. While it's definitely likely this was no coincidence, I think given that the MC2 costume and identity predates and even inspired the MMU version it's fair to count this as an adaption. It's at least more clear cut then other examples.
It seems Stinger doesn't have any unique voice lines and I can find no voice actor credited, which is a shame, though not unsurprising for a bonus character. The more curious detail is the omission of any other MC2 characters in the game, considering the plot revolves around alternate universes and future and past timelines interacting. Other popular realities such as 2099 and Future Imperfect are represented along with more recent additions such as the character Spider-Gwen. But I wouldn't like to speculate about the reasons...
Luckily, good ol' maydaymemer has an answer to the lack of MC2 representation in the game, too:
Until we get a proper MC2 game, I remain
frogoat