After every international Lead Developer IceFrog implements an update to Dota 2 to reset the meta. It's to prevent players from exclusively using the heroes the pros abused. Normally, the most prominent heroes will receive significant nerfs to their abilities, but something different happened this time: the heroes only received minor nerfs. Why?
7.06 Early-Game Meta
If you take a look at the 7.06f update, you'll see the most common changes to abilities is how often they might be used. Whether it be an increase to cooldown rate or the amount of mana it consumes, their use during the early game has lessened. Why would this be the most prominent change? Well, the current meta has been leaning toward early-game capability. This doesn't mean a game can't extend into late game, but early-game capability should prevent that. Ganking, team fights, and team pushes onto tier-one towers are all strategies favored in this meta. This means heroes who are strong by ten minutes have a lot of power.
To dampen their strength during early game, I'd say these nerfs were mandatory. Take Night Stalker for example. Once the first night hits, opponents are at a disadvantage. Since most heroes don't have all their abilities available, he can competently gank a hero with little risk. This makes the carry lane a prime target. Unless the carry has wards placed and a rotation from another lane, they very well may fall behind. I believe that's why, with the exception of Sven, there are no position one heroes in the top twelve.
Despite this, I don't think IceFrog wants rotations to be excluded from gameplay. Since the 7.06 update, supports and initiation characters have received more use and are becoming more powerful. During early game, heroes like Crystal Maiden or Skywrath Mage can be deadly while having a use late-game. In order to preserve their utility, a lengthened cooldown rate and increased mana consumption would suffice.
When looking at the top twelve Dota heroes of TI7, you'll see something rather interesting. Nearly half of the selection has less than a fifty percent win rate. You'd think that the most common heroes would have at least a sixty percent win rate to be used so often. Instead, we saw heroes being picked for function over win rate. Because of this, it's plausible that IceFrog didn't see any strategies that can be abused. In fact, despite there being the top twelve heroes, there was a high selection variance between characters. When a hero is nerfed to the ground, it's to ensure they don't control the meta of the entire game. No character should have a guaranteed positive win rate. Otherwise, what's the point of variety?
As proof of this, Faceless Void has a thirty-nine percent win rate. During the group stage events, Void was picked repeatedly. Teams would try multiple strategies focusing around his Chronosphere ability. Despite him being repeatedly picked, strategies based around him would lose frequently. As a result, when the main stage events began, his pick rate declined. This proved that there wasn't a single ability among characters that would guarantee a win.
We're still unsure if this will be the final gameplay update before the release of the new characters, but for now it's merciful. This would be a model update by my standards. When variety is prevalent and no one strategy is dominant, the game is doing well.