From the first episode alone, that the mark would be a baby from the same species as Yoda. This is notably significant as the franchise up to this point wasn't allowed to explore Yoda's past or give background of his species. In fact the last expansion of lore in relation to Yoda or his species in canonnote Knights of the Old Republic, now part of Legends (and thus non-canon), had another male, Jedi Master Vandar Tokare was in The Phantom Menace, which featured Yaddle, a female member of the species and part of the Jedi Council. Even then Yaddle's only other appearances after that has been in Tales of the Jedi, and it ends with her death.
In Episode 7, the appearance of Death Troopers and a whole legion of Stormtroopers. Up until this point the story had been a lower deck episode involving mercenaries and small-scale, personal conflicts. The fact a Moff shows up with a platoon of Death Troopers imply that there is far more going on than a simple dad and son relationship.
Chapter 8 now ties the live-action show to the animatedshows by revealing that Moff Gideon is in possession of the Darksaber, a Mandalorian relic last seen in the hands of Bo-Katan Kryze.
After having spent the last six years under an unknown fate, Chapter 9 ending with the reveal that Boba Fett is alive.
Chapter 11, Bo-Katan is back and she's after the Darksaber.
Chapter 13, Ahsoka is revealed to still be hunting Thrawn.
Chapter 14, Boba and Jango are officially revealed to be Mandalorians, after years of Canon stating that they weren't — although it should be noted that the individual who stated that was an Unreliable Narrator who had plenty of reason to say that Jango wasn't Mandalorian. And then they turn around and further clarify in Chapter 16 that Jango was an ethnic Mandalorian but Boba doesn't identify as such.
Chapter 15 has Din Djarin intentionally violate the Creed for Grogu's sake, removing his helmet when the Imperial terminal requires a facial scan to avoid shutdown.
Chapter 16 ends on one, with none other than Luke Skywalker himself coming to the group's rescue and taking Grogu to be trained.
Chapter 18 ends with the first-ever live-action depiction of a living mythosaur — an absolutely massive beast that lives up to the Mandalorian legends placed upon it.
Chapter 20 shows Grogu's rescuer—Kelleran Beq, as reprised by Ahmed Best from the Jedi Temple Challenge game show.
Chapter 21 ends with The Armorer—the same person who threw Din out of the covert for daring to take off his helmet—asking Bo Katan to do the same so she can reunite the Mandalorian people scattered across the galaxy.
