To be fair, it's not that the original Rambo movie couldn't be improved upon. I have read that the ending - the movie's weakest part - is rather different from the novel, on which it as based and in which Rambo dies. So there is room to do things differently, not least because post traumatic stress disorder of war veterans is a much better understood phenomenon than 30 odd years ago.
Ah, who am I kidding. It's going to be a cynical cash-grab.
That sounds really odd, but I have read this quote elsewhere in a different context and think it is just supposed to mean that the movie character could be played by different actors throughout the series.