I agree that nerfing mass Ravens was a good move. As well as removing Mothership core. But if you look at all the changes in the game mech is actually far weaker on the test patch compared to live.
In TvT mech is slightly weaker. The old missile costed more energy and could only damage, not kill a Tank. The new Raven can disable more tanks which is an advantage for the bio player since they can invest more gas into Ravens. And Ravens will no longer have pdd which means that pdd cannot protect your tanks from mass bio.
In TvZ mech is weaker. Mass Ravens were OP but they were also the one unit that made it possible to fight against Zergs late game. Not having auto turrets and missiles will make TvZ almost impossible. Shredder missiles are close to useless compared to those abilities and scrambler missiles will have almost no meaningful use. Swarm Hosts being slightly slower off creep will have almost no impact.
In TvP mech will go from really weak to completely dead. The new chrono boost combined with higher stalker damage and offensive shield batteries will make it completely impossible to go mech. You will not see mech in a single high-level game in TvP except in the first few weeks after the patch when no one knows what they are doing.