I was curious about Vlad’s interpretation of if Obi-Wan (and by extension Yoda) were wanting or expecting Luke to kill Vader, so I tried to see if I could find Lucas saying anything about it. I did manage to find this quote from Lucas in the Making of Return of the Jedi book.

“The mission isn’t for Luke to go out and kill his father and get rid of him. The issue is, if he confronts his father again, he may, in defending himself, have to kill him, because his father will try to kill him. This is the state of affairs that Yoda should refer to.”

I think that lines up with what Vladius is saying.