• The episode title is a reference to the series title, “Star Trek: The Next Generation”.
• The PIC series finale was also a reference to TNG, titled “The Last Generation”.
• This is the 50th and, ostensibly, final episode of LDS, making it the ninth completed Star Trek series.
• The fleet of Klingon Birds-of-Prey all appear to be the same arrangement as the HMS Bounty, introduced in “Star Trek: The Search for Spock”, though it’s unclear what specific class they are.
• The one exception is Relga’s flagship, which is larger than the others, and has a number of noticeable differences.
• We’re introduced to Relga, who is the sister of Dorg and Bargh, introduced -- an killed by Ma’ah -- in “wej’Duj” and “A Farewell to Farms” respectively.
• Like her brothers, Relga has a pet targ.
• The rift directed to the prime universe by William Boimler in the previous episode, “Fissure Quest”, opens up in front of Relga’s fleet.
• The IKS Krtas is struck by the energies emitting from the rift, causing it to transformed into a 23rd century Bird-of-Prey, first seen in “The Butcher’s Knife Cares Not For the Lamb’s Cry”. Similarly, the ship captain’s armour is altered to be that of one of T’Kuvma’s followers, which we first saw in “The Vulcan Hello”. The captain himself loses his hair, but appears otherwise unchanged.
• Rutherford expresses disdain for the USS Cerritos’ older systems being unable to properly interface with his implant. This issue was mentioned earlier this season in “Shades of Green” and “Fissure Quest”.
• This is also a reference to the modern day issue of trying to get both bluetooth headphones to pair with your phone while on your commute.
• We get a repetition of the moment at the end of the previous episode where Boimler receives the message from William regarding the imminent destruction of the prime universe, though this time we get the other lower decker’s reactions.
• Malor and Ma’ah were able to properly attach the animal tusks they had to their blood wine delivery truck, the task they set to at the end of “A Farewell to Farms”.
• ”Wake me if Kahless makes another appearance.” The clone of Kahless appeared in “Rightful Heir” and was installed by Gowron as a figurehead emperor. He was still emperor as of DS9 season four’s “Sons of Mogh”, but Malor’s comment implies that might no longer be the case.
• ”Sorry brother, but today is not a good day to die.” The iconic phrase, ”Today is a good day to die,” was first said in Trek by Worf in “Sins of the Father”.
• The Airolo scientist is voiced by Gabrielle Ruiz, who is T’Lyn’s voice actor.
• The rift’s Schrodinger field transforms the Cerritos into:
• A Freedom-class starship - A wreck of the Freedom-class was previously seen in “The Best of Both Worlds, Part II”, though it did not have a deflector dish, and only one pylon connected the saucer to the nacelle
• A second Freedom-class starship, with more yellow on the hull
• A Terran Empire California-class - According to “Crossover”, the Terran Empire fell to the Klingon-Cardassian Alliance after Emperor Spock’s reforms weakened it, meaning there shouldn’t be a Terran Empire in the 24th century to have built the California-class, but presumably if there are infinite quantum realities, there exists one where the Empire didn’t fall
• A Sovereign-class starship
• An Oberth-class starship
• A Galaxy-class starship
• A Miranda-class starship
• Doctor T’Ana explains that the reason Relga’s ship does not appear to be changing is, ”It probably is; Klingons hardly ever update their fleet designs. They always want their ships to look like big stupid birds.” The Klingon Bird-of-Prey introduced in “Star Trek: The Search for Spock” was intended to be a Romulan ship, calling back to the TOS Romulan Birds-of-Prey. Even once the decision was made to have Klingons be the antagonists of the film as opposed to Romulans, early drafts of the script made it clear the HMS Bounty was a stolen Romulan ship.
• One of the Klingon ships is transformed into a barge similar to the mythical Barge of the Dead seen in the VOY episode, “Barge of the Dead”, but this one has a mast.
• Olly is able to take down the Klingon shields, exposing them to the effects of the rift’s energy. Relga and her crew transform into mindless proto-Klingons, much like word did when de-evolved in “Genesis”, and her targ turns into a clam.
• ”Klingons do not hug.” All through TNG and DS9, Worf made several such proclamations regarding things that Klingons don’t do, most of which they actually do, but he’d prefer not to acknowledge the fact.
• Outside the stabilized rift we see:
• A second California-class starship
• A Parliament-class starship
• A Luna-class starship
• The USS Enterprise E
• Starbase 80
• Captain Freeman is reassigned to Starbase 80 to oversee missions going into the rift. She learned her alternate self from the Minor Universe had been assigned to Starbase 80 in Dos Cerritos and preventing that fate became something of an obsession for her, as we saw in “Starbase 80?!”.
• Rutherford had his implant removed, and his face reconstructed. Shaxs ripped Rutherford’s original implant out of his head in “No Small Parts”.
• T’Lyn notes romantic attraction between Rutherford and Tendi, but Tendi states they’re just friends. “In Parth Ferengi’s Heart Place” we saw that their attempting to pretend to be a couple led the pair to be extremely awkward.
• We see Karavitus wearing a Chu Chu shirt. The Zebulon sisters performed the Chu Chu dance aboard the Cerritos in “Terminal Provocations”.
• O’Connor drops out of a portal in sickbay without his boots on. When he ascended in “Moist Vessel” his steaming boots were left behind.
• The practice of Twaining began in “Something Borrowed, Something Green”. Boimler and Rutherford were banned from twaining, but we see other characters, including Lundy, Big Merp, and Federov have taken it up.
• In Castro’s quarters, we see one of her salons, where apparently they’re attempting to summon an anaphasic lifeform from an ancient candleholder, similar to Ronin in “Sub Rosa”.
• Ransom has been promoted to captain.
• Ransom makes both Mariner and Boimler provisional first officers. When Captain Ramsey was briefly in charge of the ship, she selected Mariner to be her first officer.
• We see Fletcher serving aboard Starbase 80. He was last seen in “Terminal Provocations” where he was fired almost immediately after being transferred to the USS Titan, and sent back to Earth.
• Ransom chooses ”Engage the core” as his signature command for warp speed.
Ah, that was my second guess.