I found this article about the MTM show: How The Mary Tyler Moore Show reinvented the sitcom in just 10 episodes which does include the "Ted Has a Change of Heart" episode. Although one of the best insights comes from a comment after the article:
"The Lars Affair" is actually Sue Ann's first appearance, and the most amazing thing in it is this: when Phyllis is telling Sue Ann that Lars has his flaws, her example is that he has "a neurotic fear of swallowing hair".I totally missed the implication of that too. I'm impressed episode writer Ed. Weinberger got that in there.
Here is Betty White talking about being cast in the Mary Tyler Moore Show near the end of this video at 25:25.