Hmm, wasn't there that Microsoft Windows(?) bug that they derestricted before the patch was out? Memory escapes me at the moment. I thought it somewhat cemented/promoted their adherence to 90 days regardless of patch availability.
Project Zero evaluated and relaxed their disclosure policy after that incident as described here https://googleprojectzero.blogspot.com/2015/02/feedback-and-...
I see there's some extensions there (maximum of 14 days) but this bug would have probably been covered under "As always, we reserve the right to bring deadlines forwards or backwards based on extreme circumstances."
Thanks!