Just because it's possible to program the AI to target specific characters, doesn't mean they actually did.
There are alot of players convinced there's an AI advantage for example. I have no doubt that it's possible to code an AI advantage, however the devs have always denied they did. I've no reason to believe they're lying about that. Still, players are 100% sure there is an AI advantage.
I also have no reason to believe raid han actually targets specific characters more often than others. I'm sure the devs are capable of coding it. As far as i know the devs haven't commented on this though. But even if they did, it's not like that would convince some players if they say it's totally random (no weighted odds).
I use rex lead and he's not getting targetted more often. Until recently he was the fastest character of the team. So based on people's suspicions, he should have been targetted more often. So yea...
Seeying as the AI is terrible, i highly doubt they coded it, so i'm chaulking this one up to confirmation bias.