I doubt it will try to portray terrorists in general as sympathetic figures. Harrison in particular, yes.
It will be more about the impact of terrorism on our society, the changes it causes and how we should cope and overcome its effects.
A relevant quote from Damon Lindelof in a recent interview
…we understood when we did it in the first movie that it was going to have a 9-11 level impact on that universe. In the same way that 9-11 happened over ten years ago, but we’re still talking about it and it still influences everything about our daily lives…Anything that happens in our new timeline has to walk in lockstep with Vulcan was destroyed and what is the impact of that on the federation? And what is the impact of that on Spock? What is the impact of that on Kirk? What is the impact of that on the geo-politics of the galaxy itself?