These 3 lines may be more cause for speculation than many others in recent Star Wars especially Obi-Wans statement that Luke in The Chosen One but well break that down in another piece.
Why does obi wan say luke is the chosen one. To this end he might have considered it better to Bend the truth a little and tell Luke that Darth Vader killed his father rather than that Darth Vader was his father. We all know its Anakin Filoni says firmly. Obi-wan wanted Luke to fight against the Empire and The Dark Side.
Obi-Wan thought that since Anakin turned to darkness he couldnt be the Chosen One. We know Obi-Wan stretched the truth but come on there was no reason to lie about it. Obi-Wan eventually doubles down on his commitment to Luke by making the ultimate sacrifice.
So did Qui-Gon and a few other Jedi masters. In Return of the Jedi Obi-Wan tells. Obi-Wan lamented to a freshly minted Darth Vader in the climax to Revenge of the Sith.
George Lucas always said that Anakin Skywalker is the chosen one but Luke Skywalker carries the traits of the chosen one because he is his son. Jedi and Sith commonly believed that the Force determines everyones lives and I feel that Kenobi was chosen to somehow endure and suffer throughout his whole life while trying to adhere to a Jedi code he starte. Luke wasnt chosen - he just happened to be the first to get around to you know train to become one.
Obi-Wan shouted at Anakin Skywalker You were the chosen one. He doesnt he just deduced Obi-Wan was on Tatooine protecting someone and asked if the someone was the Chosen One as he died. What about Anakins triumphant son Luke Skywalker.
Thats what your uncle told you. Knowing Obi-Wan has a purpose on Tatooine Maul says tell me is it the chosen one Obi-Wan answers. Throughout that conversation with Luke Obi-Wan contrasts Lukes adventurous father with his boring uncle.