Confused. Does this mean that no P85D deliveries in December will have next-gen seats? If they're talking about mid Jan for people getting deliveries today then won't this shortage cascade? I'm not interested in taking delivery of an incomplete car.
Piecing it all together, I think this is the situation:
1st batch of P85D with production 11/21-11/26 got built with defective Next Gen seats. These cars are sitting at the factory waiting for replacement Next Gen seats, but those with travel plans or cross-country deliveries are being offered the option to take delivery with regular seats now with retrofit next month when the replacements are available. I haven't been called yet, so perhaps they think the replacement seats for my car will be ready by the end of the year.
2nd batch of P85D with production 12/1 week and later are built with newer Next Gen seats (issue resolved) and are following the standard 5 day production cycle. These will be delivered in December at the usual pace and timelines.