Few Star Trek projects have been set in the "Lost Era" before Star Trek: Section 31, but Star Trek: The Next Generation has occasionally referenced this elusive part of the Star Trek timeline. Star Trek: The Next Generation season 6, episode 14, "Tapestry", spends a significant amount of time in the "Lost Era", when Q (John de Lancie) takes Picard to his first year out of Starfleet Academy, in 2327. Wesley Crusher (Wil Wheaton) views a posthumous recording of his father, Lt. Commander Jack R. Crusher (Doug Wert), in TNG season 4, episode 2, "Family".
Section 31 Could Introduce Young Picard To Star Trek
Star Trek Would Have To Recast Young Jean-Luc Picard
Star Trek: Section 31 could introduce a younger version of Jean-Luc Picard to Star Trek. Depending on when Star Trek: Section 31 takes place, Picard would be either a Starfleet Academy cadet or in the early days of his Starfleet career. Promotional material doesn't include a younger Picard on Georgiou's Section 31 team, so if Picard is anywhere near Star Trek: Section 31's action, it's most likely going to be just a cameo. An Easter egg might reference Picard as an ensign aboard the USS Reliant, or even the young Captain of the USS Stargazer, if it's after 2333.
Star Trek: Section 31 features 33-year-old Kacey Rohl as the future USS Enterprise-C's Captain Rachel Garrett, previously played by Tricia O'Neil. The Star Trek novels place Garrett's Starfleet Academy graduation around 2315. Assuming Garrett was about 21 when she graduated, and in her 30s during Section 31, the setting of Star Trek: Section 31 could be anywhere from 2324 to 2333.
While Picard appearing in Star Trek: Section 31 is unlikely, it might not be that far out of bounds for Picard to have a history with Section 31. TNG's "Tapestry" showed that Jean-Luc was far more reckless in his youth than the distinguished USS Enterprise Captain that Picard eventually becomes. Section 31 agents aren't really allowed to retire or even refuse service, so Captain Picard's morals aren't really relevant if Ensign Picard jumped at the chance for espionage. Picard's secret mission in TNG season 6, episodes 10 & 11, "Chain of Command", might have even been a Section 31 operation.
Young Picard Allows Star Trek To Bring In Young Jack & Beverly Crusher
Picard And Jack Crusher Were Best Friends On The USS Stargazer