For 3.2, there's no removal to document - we asked MvL to drop the buffer APIs from PEP 384, so they've never been part of the stable ABI.

From the PEP: "The buffer interface (type Py_buffer, type slots bf_getbuffer and bf_releasebuffer, etc) has been omitted from the ABI, since the stability of the Py_buffer structure is not clear at this time. Inclusion in the ABI can be considered in future releases."

I agree we shouldn't be hasty in making even the updated buffer interface implementation officially part of the stable ABI. Better to leave it out for 3.3, get some real world feedback on the latest version, then commit to stability for 3.4+.