When will the GRE Subject Test resume after COVID-19? A far as my research can find, ETS has waived rescheduling fees for taking the GRE and has canceled all test dates for all tests through September 2020. They also have an at home option for the general test. However, I am unable to find any information regarding what the future of the subject tests will be. I need to take the mathematics subject test pretty soon to make certain application deadlines, and cannot find information anywhere I have looked regarding when it will be available again.

My questions are these. When will we be able to register for the subject tests again? If this is unknown, is anything known regarding the future of the test?
ETS has now clarified their policy -- no subject tests until April 2021 at the earliest. As stated in the comments (and at the link), test takers should contact their prospective grad schools for instructions about how to proceed given this.