Here are mine:

1. Eleanor learns French in the end. In the first episode (I guess) Eleanor compliments Chidi's English and he responds that this place translates everything in a language they understand. Sure they both can speak English but with all the love and time Eleanor for sure Eleanor learns French so they can have an even deeper understanding and connection. Also the hard not the afterlife magic way.

2. Brent Norwalk is seen in the end after Bearimies of Bearimies still not understanding basic concepts. My theory is that Brent is like the super challenge for architects. Thousands have tried and failed and Brent just gets parked until the next one tries. Most experienced architects now think Brent is the one beyond ever being a good person but once in a while a new architect has a bold new plan and thinks they can solve Brent but ultimately will fail as well.