AD champions lose the 5% bonus AD mastery, too. More importantly, AD items weren't just buffed. They were rebalanced. Infinity Edge and Essence Reaver each lost 15 AD, and Essence Reaver lost its life steal (can't get health+mana from the same AD item anymore). Other items built from BF Sword lost 5 AD. Many items lost attack speed. Full builds now have less AD, less attack speed, and more crit overall, which makes them less ridiculously fast at taking towers and less effective against Randuin's Omen.
AP items, on the other hand, rather than getting stat reductions, mostly just got price increases. All damage is harder to build. It's just more possible on the high end for AP champs.
As for losing the CDR in the offense tree, well, I guess that's true, if you consider Ferocity the offense tree. Realistically, a mage is going to want either Merciless (damage) or Meditation (mana regen) from the Cunning tree, and it's not a stretch to go from there to Bandit (bonus gold for those more expensive items), Intelligence (+5% CDR, increases CDR cap by the same amount) and any of the Cunning Keystone Masteries. What you're giving up by not going deeper into Ferocity is 7% mpen (Merciless is better for damage) and Deathfire Touch (Thunderlord's Dance is better for burst, and Stormraider's Surge is better for kiting/chasing). Going 18 Cunning doesn't stop you from picking up Sorcery, Feast, Natural Talent, and Oppressor or Bounty Hunter, so you're getting everything you want out of Ferocity anyway, and you still get that CDR (45% cap, too).
So, to answer your question, they're NOT. The context of these changes is important.