A lot of people get antsy about sexualized fanservice, and often for good reason. The problem with sexualizing your characters is that it tends to sexually
objectify them. Objectification is dehumanizing, and that's pretty much always bad.
The reason why I think Blizzard does a good job, or atleast a better job than most is in these two pictures. Widowmaker is fairly sexualized in her design and this is consistent with most of her outfits. The Huntress and Comptess ones are the only ones who I feel are set to a design that doesn't sexualize her. The default, ballerina, Talon, and now this swimsuit sexualize her body to varying degrees. And while I can see the design themes adhering to one archtype or another, it's debatable whether being so sexualized is an integral part of her character.
If every female character was as sexualized as Widowmaker, this would be a major problem.
But instead, you have Sombra. She's not really sexualized in any of her outfits. And if there is any pretense that blizzard could get away with sexualizing their characters, a 'beach event' is basically the one because that's where people tend to show off their bodies even if they're not typically sexual characters. But Sombra is wearing a swimsuit that doesn't do that at all. While showing feminine curves, I don't feel this outfit is sexualized beyond that.
And that's the ultimate thing. The Women of the overwatch universe aren't defined by their sexualization...Only Widowmaker is. Maybe D.Va too, but that's it. It's the fact that they have diversity, women who are sexualized and women who are not, that makes this whole thing easier to accept, atleast for me. It's not perfect, but it feels a lot less objectifying when it's clearly not something that is applied wholesale just because a character is a certain gender.