I disagree wholeheartedly and felt that the montage was perfectly suitable for me to understand what was going on. When I pick up a book, I jump in the middle of someone's life as well. I needn't read all 11 years of Harry Potter's life with the Dursley's to understand that he was in a bad spot and what it would mean to him to be away from them.
On another note.
If they let you play out the 6 months they showed. All of those events happening. Lets say they give you twelve hours of extra content to play through. Wonderful you think. But would that really be able to tell how much time has passed? Because if I was given 12 hours of content, I'd knock that out on a saturday. Wouldn't feel like like six months. If I were a Nomad I would've just gotten to know Jackie and then go through, in the end, filler missions with him.
We come in to the story where the plot needs us again. A timeskip is a narrative device. The Avengers End Game for example. They didn't show what happened inbetween Infinity War and End Game. They skipped ahead a few years. Then they spent 20-30 minutes on showing the world after Infinity War. Did you really need more? Did you really need a few other characters to show up and tell the audience how half their family being gone has effected them? Ofcourse not.
And on a final note.
It's a roleplaying game. That requires a bit of effort from your side too. The narrative said: "Hey, you have been with Jackie for 6 months now. You've laughed together. Cried together. Fought together. It's been a wild ride. And here you are at a mission where you two will work together. Let your adventure begin."
You can also just go: Ok, so I have been with Jackie for six months and we are a team. Cool, I can work with that. - Adjust your mindset. Go from there.
