I've tested similar scenarios with my autonomous cruise and it depends how early the other car switches lanes. .... I would never take it as a given though.
Irrespective of my dislike for cruise, I think you have taken the correct approach.
But, as the vid says, not a problem for people using auto pilot correctly...........................
As I watch the modern drivers asking our advice, I conclude many driver's have little driving experience, little intelligence or are impractical to the point of utter stupidity.
Yours faithfully, Benevolently Cynical.