Wasn't Arc like not meta until this tournament? TB/PL/Morph sure but I thought Arc Warden was kinda recent. It's super strong but it's not like it's been constantly around to get bored of already imo. Should get nerfed though probably, just too good atm.
Was only played 3times in the whole main stage, with only 10bans too and Topson won with it in WB finals, not even grand finals. Interestingly enough, that's more than TB and Morphling too. TI had a way different meta than the current one, at least in terms of carries. There was a patch that nerfed a bunch of the common ones inbetween(Spectre especially), they just switched and have been the same for a while but not since august.
Slark got A LOT of buffs it seems, just from general mechanics change. Seems he can dispel Hex again and pounce is now a TP interupt, which means there's no escaping him if he ganks you at low hp/you're a support. Also got some minor buffs directly but those are pretty big.
Some of the changes seem super retarded but we'll see I guess. AM reflect on a 3secs cd 1.4secs duration, SD straight up removing 40% health from people for 10secs, Huskar having an aoe knockback+disarm+damage on a 12secs cd, Dazzle having 50% cooldown reduction, Brew drunken haze being way way stronger, Razor having a 500aoe 120damage free nuke every THREE seconds, definitely some wild shit in there. Some of the changes look a lot worse too. Like OD seems even worse somehow?