Thawne notes that Ralph should be dead, which he was, a reference to Power Outage (2014), where he revealed that Ralph was one of the people who died from the particle accelerator until Barry created Flashpoint.
Barry gives Nora the same speech Jay Garrick gave him after he stopped him from trying to fix Flashpoint (again), this is the second time he tells her this, the first time being Cause and XS (2019).
Cisco mentions the idea of playing Gaga to wake Ralph up which refers to when Caitlin and him played Gaga to wake Barry up back during Pilot (2014), in 2049 Nora's friend Lia played Gaga to wake her up in Godspeed (2019).
Thawne mentions that " this is the second time that I've been stuck somewhere for 15 years", a reference to S1, when he was stuck in the 21st century from 2000 to 2015.
Thawne also halfheartedly apologizes for the time he killed Cisco in an altered timeline, referencing to Out of Time (2015). He even mentions that Nora was like a daughter, in a similar way that he spoke about Cisco being like a son to him, saying that she taught him what it was like to have a daughter.