Welcome! Sadly you've already hit peak kpop, it's all downhill from there!
Damn. SNSD was the group that got me into KPOP. Sad to see those three leave. Especially Seohyun She was my favorite of the three.
Start with the Essentials and Classics playlists in the OP. :)
Did you turn left when you should have turned right?
Really depends on if SM feels it is a group worth keeping going. I’ll have to read up on how SNSD has been doing these past few years to give my opinion but I would imagine that there is a decent chance of the group being scrapped. It certainly won’t be the same without those three.