When he was first announced I was a little annoyed, but I'm fine with it now. My appreciation for him was renewed when I heard about all the licensing headaches - he was probably one of the easiest characters to get the rights for. XD
Plus he seems pretty charming, and I like the idea behind his fighting style, with stance-changes giving you different moves without completely changing your moveset. : D
They didn't have to get the rights considering he is created by Sony.
They still had to get permission from whoever created him/developed his game.
It's not like Media Molecule would've tolerated a sackboy armed exclusively with a chainsaw spear who was a close-range character like Raiden.
We also saw how pissy Suckerpunch got when Superbot only wanted Good Cole.