Why almost every major change in game seems to be leading to assassin meta?

Void Superbuff - intended for junglers. Works best on assassins. Tower changes - tower are now tankier. Unless you are an assassin that is, than they are much squishier for you. Zhonya nurfed - no need to say more. Rod of ages nurfed - also great buy vs an assassin. Used to be, that is. Vision wards nurfed - it's not significant, but makes this list appear longer. Kappa - it does matter for stealth champion.

And last but not least:

QSS no longer removes Death mark - luckily Riot is already aware that Zed is gonna be broken. It's not like they intend to do anything about this or anything, but they expressed that they are aware.