In the early days of Sesame Street when I had a child who was the age to watch, I complained to my own father that Jim Henson was probably gay, because the only female main character on the show was Miss Piggy. My dad thought that was a terrible thing to say because he played golf with Jim Henson's father—LOL! The Christians in this country were so naïve until recently! Eventually Sesame Street improved the image of females on the show, but up until then, Miss Piggy was like an early version of Drag Queen Story Hour.
In the early days, before the Muppet Show, Sesame Street didnt have much in the way of leftist content. It was mostly just little bits about a number and a letter and little humorous skits (Grover cant get the sandwich he ordered) in between. The show slowly morphed to include other things as time went on so I doubt that any alarm bells had any reason to go off. The last time I had seen an episode, quite a few years ago, the show had very little of anything but propaganda. The bit I found disturbing was a cartoon called something like “World Thingy”. It was a cartoon about a anthropomorphized UN symbol that flew around forcing its version of fairness on the little creatures of its environment. Nothing like programming them while young. I didnt let my kids watch the show after that.