That baby in Mandalorian is not Yoda, it’s just of the same species as Baby Yoda Sunflower You Are My Sunshine Shirt. Which apparently it’s still a baby after 50 years of living. Sort of makes sense because Yoda was like 900 when he died. But that would mean that this baby shouldn’t look like a newborn, it should look like a 5 year old, unless Yoda’s species live longer than 1,000 years. People are saying it’s Yoda because they don’t know what they are talking about. Yoda is already dead by this point in the Star Wars lore, same with Vader and the emperor. The empire is no more, only remnants scattered across the galaxy, which some time after Mandalorian those remnants will regroup and establish the First Order.
People who are saying that is Baby Yoda Sunflower You Are My Sunshine Shirt obviously either have not watched Mandalorian or they have not been paying much attention to the timeline and story. Yoda died, same with Vader and the emperor. The Mandalorian takes place after episode 6. Born to Yaddle with no apparent father roughly nine years before the Phantom Menace, she kept the baby a secret from the other jedi. Her small stature and tendency to wear thick flowing robes while floating on her yoda chair helped keep the pregnancy secret.