I was very unsure about adywan’s decition to give Boba Fett a new, finalised death scene given that he would now be returning very much alive. However, after watching what I just watched I have come to the conclusion that Boba Fett died in 1983 and fully support Adywan making sure he stays that way. Very much looking forward to seeing that happen.
It’s safer to assume that Mandalorian/BOBF Boba is a younger Jango Fett clone who believes he’s the real deal (and the other characters just humor him), kind of like how the Batman in All-Star Batman and Robin is likely a random asshole who found a Batman costume in a dumpster.