It’s true that comments Mark Hamill made about Luke in The Last Jedi during the press tour included statements that he wasn’t sure about his character’s direction in the new movie.
Given some context and the overall divisive reaction to The Last Jedi, the comments went viral.
Besides, if these comments were made during the press tour, then logistically there’s no time to change the ending anyway.
Hamill has since apologized and clarified his comments, but they still live on the internet forever.