What happened to the USS Discovery is still a Starfleet secret in the 24th century, which is confirmed by Star Trek: Section 31. The present-day of Star Trek: Section 31 is the 24th century, specifically Stardate 1292.4, which is April 17, 2324. Star Trek: Section 31 takes place 66 years after the end of Star Trek: Discovery season 2, which took place in 2258 when Commander Michael Burnham (Sonequa Martin-Green) led the USS Discovery on a one-way trip to the 32nd century - with Emperor Philippa Georgiou (Michelle Yeoh) aboard.
In Star Trek: Discovery season 3, the USS Discovery arrived in the year 3189 to a United Federation of Planets and galaxy broken by The Burn. Meanwhile, Emperor Georgiou discovers she is dying from both crossing from Star Trek's Mirror Universe to the Prime Universe and time traveling 930 years. The Guardian of Forever (Paul Guilfoyle) sent Georgiou back to a time when the Prime and Mirror Universes were still aligned, thereby saving Philippa's life. Meanwhile, the truth about the USS Discovery remains redacted by Starfleet in Star Trek: Section 31.
Star Trek: Section 31 Confirms What Happened To USS Discovery Is Still A Starfleet Secret
The Truth About The USS Discovery Is Safeguarded
After Star Trek: Section 31's flashback prologue to how young Philippa Georgiou (Miku Martineau) became the Terran Emperor, Control (Jamie Lee Curtis) delivers a mission briefing about Georgiou to Alok Sahar (Omari Hardwick) and his Section 31 Alpha Team. Control says, "In 2257, she was brought to our universe and joined Section 31, but after a few years, we lost contact." This indicates Starfleet and Section 31 did not know about Emperor Georgiou's roundtrip to the 32nd century with the USS Discovery.
However, it's also possible Control does know about Georgiou's time travel, but did not disclose that information to Alok Sahar's Section 31 team. Starfleet's official cover story after the end of Star Trek: Discovery season 2 was that the USS Discovery was destroyed at the Battle of Xahea in 2258. Captain Christopher Pike (Anson Mount) and Lieutenant Spock (Ethan Peck) of the USS Enterprise maintained this fabrication in 2259 as seen in Star Trek: Strange New Worlds, and only the highest levels of Starfleet know the truth - but this could include Section 31's Control.
Section 31 Glosses Over A Big Emperor Georgiou Question
Emperor Georgiou's Age Never Comes Up
Star Trek: Section 31 doesn't acknowledge that Emperor Philippa Georgiou, who is confirmed to be human, should be decades older than she appears. Star Trek: Discovery seasons 1 and 2 took place from 2256-2258, and this was the last time Starfleet saw Georgiou. Philippa's reappearance in 2324 looking exactly how she looked 66 years prior goes unmentioned. Alok Sahar revealing to Georgiou that he's "not of this time either" is the only hint that Section 31 could be aware of the Emperor's time travel.
