If the book shown in the trailer for TLJ are from the dawn of the Jedi Order, and if that book is the Journal of the Whills then we will have a link back to the Old Republic times, that could spark a very pre prequel series.
That's my concern. Too much is already Canon around Han Solo. Even if they make a great movie we'll all be sitting there ticking off key moment...
Won the Falcon - tick
Kessel Run - tick
Saved Chewie - tick
It feels restrictive.