In the first season I heard them say they based Yoo Babi's character on the show with some bits of Soonrok. I have  not read the webtoon so i do not know how true that is. They might still introduce Soonrok this season but it might be rushed if that is the case.

There will be no 3rd season. They started shooting 2nd season just after 1st one ended and all the main actors are already involved in some other projects. If Soonrok appears in the show, probably it will be only for two last episodes. If not, we can expect 2 options: Yu Mi ending with Babi or with Go Woong. Ending alone is not an option, as in the first season cells showed Yu Mi's wedding photo. 

 Dramaholic:

There is no formal announcement of season 3 but I was mentally preparing for another heartbreak and hedging my bets on who is going to be casted as Soonrok because both Go Woong  and Babi are very well casted. On one hand, I want her to end up with either Babi or Woong, on other hand, I can see how problematic each of their relationship got and I want better for Yumi. I am honestly losing my shit over this drama! 

same here

disappointed to say the least...