The meeting between Captain Jean Luc Picard and Ambassador Sarek of Vulcan in Star Trek: The Next Generation could have significant repercussions for the USS Discovery's mission in the future. In The Next Generation, the two leaders share a mind meld in order to help stabilize the Vulcan leader; however, because Sarek shares a telepathic link with his adoptive daughter Michael Burnham, it's possible that the Picard and Sarek mind meld may have put the USS Discovery in danger in the future — particularly from the Borg.
Sarek is the father of Spock who first appeared in the Star Trek: The Original Series season 2 episode “Journey to Babel.” When Sarek appears in the Star Trek: The Next Generation season 3 episode “Sarek,” the crew discovers that Sarek is afflicted by a rare degenerative neurological illness, Bendii Syndrome, which causes loss of emotional control in Vulcans of his age. With Sarek's diplomatic mission in jeopardy, Captain Picard volunteers to mind meld with Sarek to temporarily strengthen his emotional control, and in doing so inadvertently sets in motion a sequence of events that spells disaster for the crew of Star Trek: Discovery.
Star Trek: Discovery “Battle at the Binary Stars,” established that Burnham and Sarek have a shared telepathic link resulting from previous melds. Sarek, with this link and his political position, likely had detailed intimate knowledge on the fate of the Discovery, possibly even about Control itself. Some of that information could have been passed on to Picard, and just months after their meld, that knowledge would have been assimilated into the Borg collective when Captain Picard was abducted in the Star Trek: The Next Generation season 3 episode “Best of Both Worlds.”
Star Trek has established Vulcans have many unique abilities due to their anatomy, including the mind meld technique. The sharing of minds brings knowledge to each participant, but this sharing comes with risks: from a loss of identity, to a manifestation of detrimental psychological afflictions, and in some extreme cases, an enhanced telepathic link extending over many light years, as shown in Star Trek: Discovery. So, when Captain Picard assisted Ambassador Sarek with a mind meld to stabilize the affliction that was threatening to derail his final diplomatic mission, their sharing inadvertently embedded dangerous information into Picard’s mind, things the captain should never have known; retroactively, that presumably included knowledge of Michael Burnham and the USS Discovery’s mission to the future. This includes the sensitive information about Control and the highly-prized information onboard Discovery's computer: the sphere data.
With the Borg in possession of Picard’s memories, including the shared memories of Ambassador Sarek, the future of the Federation and Starfleet could in fact be in greater jeopardy than the crew of the USS Discovery realize. Control was Section 31's rogue AI program that posed a significant threat to the future: not only did it take over Lieutenant Commander Airiam, but it proved basically impossible to completely destroy, hence why the USS Discovery fled with the sphere data to the future. Control is a bodiless equal to the Borg, and thanks to Sarek, the Borg have had roughly 800 years to prepare to assimilate it — and plan to go after the sphere data as well. If the Borg do exists in the future when Star Trek: Discovery is set, it's likely they'll stop at nothing to assimilate the Discovery's sentient computer and unique spore drive. Thus, the seemingly innocuous events of “Sarek” in Star Trek: The Next Generation have potentially doomed Star Trek's future.
