SNSD next solo: SUNNY ? YOONA ?

As we know that 6 of 8 SNSD members had officially debut as a soloist in South Korea and the last one is SOOYOUNG. I'm gonna make a list about SNSD member solo debut album :

1. TAEYEON
I 
An EP, released on October 7, 2015. [1]

2. TIFFANY
I Just Wanna Dance
An EP, released on May 11, 2016. [2]

3. SUNNY 
?

4. HYOYEON
Wanna Be
A digital single, released on June 1, 2017. [3]

5. YURI
The First Scene
An EP, released on October 4, 2018. [4]

6. SOOYOUNG
Winter Breath
A digital single, released on December 20, 2018. [5]

7. YOONA 
? 

8. SEOHYUN
Don't Say No
An EP, released on January 17, 2017. [6]

SNSD next solo debut, Sunny or Yoona ?

So, who will be the next ? SUNNY or YOONA ? Both of them already released some songs under SM Station and YOONA has a mini digital album in chinese, Blossom, released on August 4, 2016 [7].

What do you want from their solo ?

SUNNY has a cute and very unique voice, but her appeareance is sexy. I don't have anything in my mind what concept and song genre she gonna gives us. But her solo performance with Britney Spears song, '3', in SNSD 1st Arena Tour was totally 'her' and better than her song under SM Station.

For YOONA, I kinda expect her to release a dance track that shows her charismatic side in the stage, but still beautiful like always. Her voice is smooth and calming and ballad song is suit for her, but I expect more from her because I know she can do that.

Have you read the rumour about SM plan for the first half of 2019 yet ? You can read that here: https://www.allkpop.com/forum/threads/rumor-sm-plan-for-first-half-of-2019.267449/

Rumour about SM plan for the first half of 2019

It is going to be SUNNY that will have solo debut in February. I don't know if it is true or not and it is still rumour by the way. Based on that rumour, Taeyeon should be the one who comeback this month alongside with SUNNY, but the fact Taemin first [8].

SNSD SUNNY ? SNSD YOONA ? I don't care who coming first, all I want is every SNSD member debut as soloist (which is gonna be a new history by SNSD) or success in their own way.