I agree with you @majinadam. If it is true that obtaining a Legendary can be somewhat difficult, but for that same reason it is much more interesting. It gives a unique mechanism to PokeMMO, I think that they finish adding all the remaining Legendaries is enough.
If it is true that more possibilities will be opened for PvP with the implementation of the Dungeons and the obtaining of the Legendaries for each player, but I still think that the way in which they have kept the Legendaries is perfect, it gives that unique touch to the play.