If I were to guess, it's likely that sales projections are down right now, and they're hoping by keeping the existing line a bit longer, new buyer numbers will be larger in the spring. Most people don't upgrade every generation and a lot of people are still running M1/M2 devices.

I would also speculate that there may be some growing pains for the n2 production from TSMC, and/or a desire to get there in the AZ fab production before launch to avoid tariffs hitting their bottom line. They'd rather pay 12-20% more for just the CPU than eat large tariffs on the full cost. I don't think they'd be able to significantly raise prices further based on tariffs, like some other companies with smaller margins are forced to do, on order to be competitive.