Why did everyone seems to freak out about this? 

It's not even shocking. I've read a comment said "Suho just being friendly." I'm sure that person is jealous. I know it's normal but

I think they're close to each other. Krystal mention him in her 'Pinocchio's Thanks To'  (before Exo debut)

My one and only family, mom, dad, and unni thank you and I love you always ^^

(My) dear BFFs Seungah, Gaeng, Yoonie, Shilla/Shiela, Minjae, Hyun!, Even if I can’t say it, you know how I feel right? 143♥ a friend for 11 years Nayeonnie, my real brother(t/n: could be translated as ‘close oppa’ as well) Jjong, Haem, Kim Akdeok (Kim Angel), Daniel oppa, Junmyeon oppa, Kyuwan oppa, Inwook oppa, Heejungie, Ssohyunnie, egg whites Jjiyounggie, thank you & I love you all!

Teacher Lee Sooman, President Kim Youngmin, Director Nam Soyoung, Director Han Semin, Director Jung Changhwan, Director Lee Jongin, watched over me since I was 7 years old Jungah unni , best Gyeongchang oppa, Ratatouille Sungwoo oppa, when are you going to buy me Rib eye (steak) Bbang/Bread-nim, Hyunkyun oppa, Minho oppa, Wonkyun oppa, Sungsoo oppa, Junghee unni, Yooeun unni, Areum unni, Yoonju unni, Eunah unni, Heejin unni, Kenzie unni, Jinu oppa, Boomin unni, Jaewon appa, Jackson Hwang! All the other SM staffs and sunbaes/seniors thank you^^

Gooyoung appa, Ssolmi unni, Rino, Jillian, Hyerim unni, when did you become pretty Hyejin-sshi, charming girl Gyeongbin unni, Seonjoo unni, Seunghwa unni, hi Mira unni, Chullie oppa, swim to me Nemo, okay & sorry Hyunjoon oppa, ‘Bul.Ae.Man' family.

Our Vic umma, it’s all good Josephine ‘stupid boy~’, Tinky Winky Lulu, my twin yolk, we know things that other people don’t know. Love you♥

Finally, our fans who cheer and love us! Really thank you. I’ll always be the Jung Soojung/Krystal that works hard!^^

Chill guys!  As you can see....she also mention Shinee Jonghyun & Dalmation Daniel.