Because the American public, as a whole, is only interested in figure skating in the winter, and only every 4 years for most members of the public.
Even at the peak of skating's US popularity ~20 years ago, I can't imagine many of the fans who might tune in to Skate America or a fall pro-am to catch up with the stars at the beginning of the season would be much interested in watching test skates let alone listening to press conferences even with Michelle Kwan in August.
Fans who populate online skating forums or follow skating and skaters on social media these days might be interested, but they're already highly invested in the sport. A promotional event in the summer is not likely to make much difference in whether we remain skating fans or lose interest. Whereas for casual fans, a test skate or press conference wouldn't even be on their radar, and if they did happen to come across one it wouldn't be likely to get them hooked on figure skating.
When the stakes are high going into international competitions, especially leading up to an Olympic season, that's when casual fans might care enough to pay attention and, if we're lucky, become interested in watching even more skating. Starting with other meaningful competitions.