In the new documentary Disney Gallery: The Book of Boba Fett, Lucasfilm president Kathleen Kennedy reveals that George Lucas advised her to bring back Temuera Morrison as Boba:
“When George first spoke to me about Boba Fett, he immediately said “I cast this amazing actor from New Zealand called Temuera Morrison to play Jango Fett”. He said “If you ever do Boba Fett, you should cast Temuera to play Boba because he’s such a remarkable actor.””
As is known, Lucasfilm followed Lucas’ advice and Morrison returned as Boba in The Mandalorian and The Book of Boba Fett.
Boba is the unaltered clone of Jango, who was played by Morrison in Star Wars: Episode II – Attack of the Clones. Morrison actually already played Boba before The Mandalorian, but only as a voice actor (in the latest versions of Episode V – The Empire Strikes Back and several video games).