PERSONAL OPINION ALERTI'm writing contemporary YA for the first time and its tough. Its a story that doesn't want to leave me alone, but I find myself asking basic questions. I assume its okay to reference contemporary movies and video games?
My gut feeling is you want to be careful with using too many references that tie your story to the absolutely current moment, lest in five years it starts to feel dated.... as an example, Warcraft or Final Fantasy are probably okay b/c they've permeated the wider culture to a degree, and have shown staying power; Overwatch, maybe not as much (I'm using myself as a guideline here - I'm not a gamer at all, and I have a basic awareness of WoW and FF while I've only heard of Overwatch due to passing mentions in one podcast I listen to).
Or: my 16yo tells me that she and most of her peers are moving off Tumblr already (to Instagram and Snapchat), and we all know that only old people use Facebook...