I don't know how a smoke helps you. BS can silence you at any point and you're fucked. Slark does his shit over time, not instantly. I mean with a blink you might get a quick support kill by unloading your shit, but you're gonna die right after if you can't get out, which is what the silence does. It's not like you can smoke in front of the BS to escape either, that's not how smoke works, if he's in range to silence you, then he's in range to dispel the smoke instantly.
I'm more surprised at the Lina not picked than any other hero personally. Kotl/CM I could have seen in some setups, the mana regen and counter pushing as well as jungling potential of both heroes is valued in certain setups(example if you want to 5man push having a CM is pretty good since she can't do her own stuff in the jungle so you get more xp out of the first 10mins and then she can buy an urn and provide strong mana regen to everyone for the push, kotl works when you have like a bunch of healers, feed them mana constantly, never run back).
Lina on the other hand is just a solid support. She's not like top tier to solo babysit someone obviously, but she's near top tier for roaming ganks, she scales fairly well and her agh upgrade is actually super good now since you can still laguna blade a bkb carry and that shit hurts. I would have expected her in agressive support roams strats and against natural bkb carriers and shit. She also soft counters EB shenanigans as long as she's not the one getting EB one shot since laguna trades well with Dagon. She has good counter push/push and you can just stack utility on her and still get good damage and control. I wouldn't say she's like really strong as a support but I'd say she's fairly decent so not being picked even once is a bit strange to me.
As for kotl in the meta, you must not have been watching very long. There was a time a few years back when kotl would even get banned sometimes. He was in every fucking games, and a lot of times he was with PL too, fucking cancer PL era. Every game was cancer and people were bitching left and right about it.