Originally Posted by A Clown
So I'm really hoping that he doesnt have that slaver background, I enjoy a corrupt route (especially for my own characters) but that's just way too evil man!

Well, they did say that this ea is meant for evil playtesting and that companions init fit that alignment (minus Gale who wasn't even meant to be a part of this ea originally).
Also, if we are to assume that backstory in regards to Astarion is still valid, it would honestly explain why Gur ambushed him in the first place. Think about it for a second. Why would Gur care to ambush some magistrate? Their job is killing monsters, not corrupt nobles. Them being tipped (most likely by Cazador who was setting Astarion up) that Astarion is working with vampires, would be something that Gur would care about enough to ambush Astarion as they did.
Also (in my opinion), this type of background for Astarion would help with making the whole Cazador case feel less one-sided. Cazador might not be the greatest man and is clearly an asshole, but Astarion would be no better than him in this case. Which would lead to the question of do you wish to support evil like Cazador just because Astarion is not sunshine himself. Or, will you still help Astarion even though he is no better than his master?
All I know is that I'm not even talking to that man without having DT (Detect Thoughts) activated. Since this seems to be the only way to get an actual truth out of this man. Like when he was trying to make himself look good by claiming that he only kills animals because he is no monster. DT reveals the actual truth behind that reason and you get to call him out on that.

In short: Whatever or no that part about his background still stands, Astarion is still full of sh*t and he is not to be trusted at all.