There has now been another letter in support of Kathleen. It's signed by some big names including Peter Singer and Cordelia Fine.
sites.google.com/view/open-letter-stock-freedom/home
Much academic research, including philosophy, engages with difficult and controversial subjects, and it is critical that this work be brought to bear on matters of real, imminent public concern. Sex-specific intimate spaces, athletics, medical services, and prisons have long been the norm in our societies and are represented in the very infrastructure in which we conduct our daily lives. Significant changes to these practices and norms are the kinds of things that our professional scholars must be able to discuss, without constant threat of public vilification.
It cannot become our standard that where analysis and discussion of matters of public concern may cause offense, the social and institutional consequences of engagement are so costly that few will be willing to do the work. It cannot become our standard that the mere allegation of harm caused by some writing or speech, in the absence of any specific evidence to that effect, is sufficient to trigger such consequences. And it cannot become our standard that the mere fact that someone who causes harm agrees with something said or written by an academic is sufficient to saddle that academic with responsibility for that harm.
The Open Letter Concerning Transphobia in Philosophy is the latest depressing example of an increasing inclination in the Academy to adopt precisely these kinds of standards. The effect can only be to discourage those whom we employ to research, think, write, and speak about these issues from doing so and to deprive students of a diverse and intellectually rigorous education. This will neither benefit our laws, regulations, and public policies nor improve the education that students receive.