Indeed, and Soldier 76 is the dad. And that's just fan joke cannon.
And another character call Pharah has a suit that looks a lot like Samus' suit.
I can tell you since I had already played the game and a fan of the game. Overwatch wiki is pretty accurate.
Ziegler rose to become the head of surgery at a prominent Swiss hospital before pioneering a breakthrough in the field of applied nanobiology that radically improved the treatment of life-threatening illnesses and injuries. It was this expertise that attracted the attention of Overwatch.
Because her parents had been taken by war, Ziegler was opposed to the organization's militaristic approach to keeping global peace. Ultimately, she recognized that Overwatch offered her the opportunity to save lives on a much larger scale. As Overwatch's head of medical research, Angela sought to leverage her work for healing in frontline crises. The result was the Valkyrie swift-response suit, which Ziegler herself piloted on many Overwatch missions.[2]
I had not played Mercy in Quick Play and Competitive at all. I often use Lucio as support.
Here is Mei with the Ice Climbers. Mei is considered the most annoying and OP character in Overwatch. Similar to how many people think of Ice Climbers in Melee.