As we all know, generation five used to be the dragons metagame, with outrages and draco meteors being fired off from every corner. In PokeMMO's current metagame, however, dragons have been nerfed heavily. The strongest user of the move Draco Meteor, Hydreigon, is unable to learn the move as previously, it had been stated to be "too overpowered" due to it having access to the move. Again, outrage went from being the strongest viable physical dragon type STAB, to now being reduced to its generation 3 counterpart as a worse, and completely unviable physical dragon type attack as its base power has been lowered from its original BP of 120 to 90, effectively making it just slightly stronger than dragon claw, but with an unfair drawback of being locked into the move for two to five turns, which is highly unjustified compared to its base power.
These facts are known by everyone, and I'm simply restating them to point out that buffing dragon types, rather, restoring them to their former power level is not a bad idea. Returning the ability to learn Draco Meteor to Hydreigon will by no means, make it overpowered, since almost every team in OU uses either Chansey or Blissey, both of which take minimal damage from the move. Not only Chansey and Blissey, even Umbreon, which has recently joined the OU tier, can for the most part deal with Hydreigon, as Draco Meteor's special attack drop allows it to survive the second hit, and successfully heal up with the combination of wish and protect. The calc is shown here for referrence,
252+ SpA Choice Specs Hydreigon Draco Meteor over 2 turns vs. 252 HP / 252+ SpD Umbreon: 329-389 (83.5 - 98.7%) -- not a KO
While I will admit that Outrage being restored to its former power of base 120 will be troublesome for teams without Skarmory and/or Ferrothorn, at present, the abundance of OU teams that utilize both the aforementioned Pokemon should for the most part negate that problem. Even besides the two Pokemon that I have just mentioned, Pokemon like Cofagrigus, Dusclops and Milotic are also more than capable of taking on boosted outrages from a mon like Salamence.
+1 252 Atk Salamence Outrage vs. 248 HP / 252+ Def Cofagrigus: 168-198 (52.6 - 62%) -- 98.8% chance to 2HKO after Leftovers recovery
+1 252 Atk Salamence Outrage vs. 252 HP / 252+ Def Eviolite Dusclops: 121-144 (42.6 - 50.7%) -- 2.3% chance to 2HKO
+1 252 Atk Salamence Outrage vs. 252 HP / 252+ Def Marvel Scale Milotic: 169-199 (42.8 - 50.5%) -- 95.7% chance to 2HKO after burn damage
Although it may seem that the aforementioned mons are in danger of being 2HKO'd by a boosted Salamence, keep in mind that Cofagrigus and Dusclops both have access to Will-o-wisp and pain split, giving them a means of crippling Salamence, and then restoring their health to be able to take further hits. Meanwhile, Milotic more often than not carries Ice Beam, which OHKO's Salamence from full.
And those are just a few examples, more such displays of Pokemon being able to deal with dragons exist, both offensively and defensively. And therefore, I see no problem in Hydreigon once again being allowed to learn Draco Meteor and Outrage having its power restored to base 120.