The Fall ‘event sequence’ crossover is quite late in the Relaunch novelverse. It pays off some storylines that had been building for quite awhile.
I didn’t jump in that late, but still found it better to jump quite a ways back to where the Relaunch took off between the later TNG movies Insurrection and Nemesis.
One doesn’t have to read everything, as there are definitely some core books and ‘event sequences.’
Most Relaunch fans consider the two David Mack books in the TNG ‘A Time to …’ series (A Time to Kill & A Time to Heal) as key foundations, then Keith DeCandido’s ‘Articles of the Federation’ set after Riker takes command of Titan in ‘Taking Wing.’
Mack’s Destiny trilogy is fantastic and is the pivot point of the Relaunch novels. DeCandido’s ‘A Singular Destiny’ then bridges to set up the Typhon Pact sequence.