I haven't been playing much recently, but I do have opinions on the card changes.
Leeroy nerf really hurts the Shadowstep combo because it's not just +1 mana, it's +1 mana every time you play Leeroy. So you can't double Shadowstep until turn 10. However, 12 damage for 2 cards and 8 mana isn't terrible (like 2x fireball) and there's also the Malygos Miracle Rogue that was around for a while. It's not like Miracle is all about Leeroy.
This kills the Leeroy+PO+Faceless combo, which means Leeroy probably comes out of Handlock decks. Arcane Golem + PO + Faceless is 16 damage for 8 mana, so maybe that's a thing...
The other uses of Leeroy weren't really pressing the mana boundaries and they probably are still fine. Overall, probably a good change.
The Buzzard one, wow. Remember when it was a 2/2 for 2, lol? 3/2 for 5 seems extreme. At 5 you can't play that many beasts to get draw out of it. I guess if you draw 2 off it, you can compare it to Ancient of Lore, but for 2 less mana with 2/3 less stats. But it's a lot more situational too... I guess comparing it to one of the best cards in the game isn't really fair. Still, it seems like if it's going to cost 5 mana, it should have a little more health, so removing it isn't so trivial -- like 2/3 instead of 3/2, or just 2/2 for 4 mana. Probably it's not actually that bad though.