If Outlander does indeed omit those 200 pages of Gathering shenanigans, the pace of Season 5 will already be faster than The Fiery Cross, and I can’t say that would be a bad thing.
The ending of Season 4 indicates that Outlander is skipping the Gathering altogether.
If Outlander addresses the need for Brianna and Roger to have a wedding more official than their handfasting and their son — who has not yet been named on the show — to be baptized, there will likely be less dramatic fanfare surrounding the events.