Stanford has not shared Yale's objections to the online notes service. The merger promised cheaper, more convenient access to lecture notes, as well as a wider range of classes whose notes would be posted.
Some people love it.
Students are paying tuition at Yale. You can't claim it's a public forum. Stanford professors have shown little concern about notes from their lectures being posted. They see the service as merely another study tool. I'm quite happy people can have later access to notes that may help them, especially as the textbook only covers so many things.