Once the Empire started, they worked hard to not only eliminate the Jedi but also used propaganda to erase their history and what they truly were. So from that time to the A New Hope, then through Return of the Jedi, then to Mandalorian, that's close to 30 years. The other thing is that for most of the Galaxy, they never saw a real jedi, just the stories.Okay love the trailer but what is up with the mystery sorcerers stuff? There is no way these people don't know about the Jedi and them not knowing about Yoda's species has always seemed odd. It has not been that long. Only five years since the Empire's end and everyone would know who the Empire destroyed to come into existence.
Also Daniel Logan is about the same age Boba Fett would be and Temuera Morrison is about twice the age he should be. Still Bob a appearing awesome.
The Mandalorian themselves have a rocky relationship and I take it that certain clans still hold grudges.