The problem with this movie is that it is just a basic revenge movie that could have been done without the character of Rambo and it would have been all the same. It doesn't have a hidden anti-war message, no real link to the reality of a veteran's PTSD nor the over the top one-man army meme that Rambo is known for.

[spoiler] I haven't read/seen anything about this movie before watching and I was expecting to see Rambo doing what Rambo does the best - many, many, many violent kills. But I wasn't expecting the story to be around the horrible sex trafficking industry, a pretty harsh subject.
Sadly, it just doesn't fit well with the character of Rambo, yeah yeah we see him having difficulty to handle the accidental deaths at the start of the movie but beside that, there's no hard link to the back-story of Rambo, the Viêt-Nam vet suffering from PTSD and turned into a one-man army just turn into a basic revenge flick. Moreover, I was happy to see him go back to the old traps and spikes so those assholes get the painful death they deserves for all those innocent life they destroyed just to see Rambo quickly end their life after being impaled. What's the purpose of the traps then? He said himself that he wanted them to suffer, just to mercifully kill them. [/spoiler]
Anyway, I just spent the last 15 minutes trying to see the meaning of this movie for the character of Rambo and I'm just losing my time.
**TL;DR: The movie's title is clickbait at best. The movie would have been the same without Rambo and there's no links to First Blood beside wood spikes traps.**