I suggest adding:

``To change the license, we obtained written permission (by email) from all past and present developers on the biom-format project. The core developers, including @gregcaporaso, @wasade, @jrrideout, and @rob-knight were included on these emails. For code that was derived from the QIIME and PyCogent projects, which are under the GPL license, written permission was obtained (by email) from the developers of the original code (tracing through the commit history, as necessary). @gregcaporaso, @wasade, @jrrideout, and @rob-knight were included on these emails.```