Why are 90% of all players tech players anyways (having 2/3 tech units, I'mma ignore the 1 unit variant)? I don't quite understand this phenomenon. The game can be played without using them, yet almost every single person below diamond 1 uses it.
I think once people can build 2 harvesters (at profile level 9), they think that this is the way to go and just keep doing it, not understanding that you can have an army with only 1 harvester.
Now to "Aggro decks are dead". I think decks without a single tech unit will have a harder time now. But decks with only 1 tech unit are now better than always. And you can still go aggro with only 5 units, that's how I have been playing all the time - 5 units for my aggro deck and 1 unit as my tech trump card. This tech unit usually never gets build, but I have it in there just in case I cannot win with my normal units. And now its cost got reduced from 120+unit to 60+unit for me, so it's easier for me to get one of them out to turn the tides.
So in general: decks with 6 aggro units will have a bad time. Decks with 4/5 aggro units + 1/2 tech units will most likely become dominant.