I'm looking to book a flight in early May, and on several days I see the following message:
The seat map for this flight is currently unavailable. Please check back later for seat assignments. Seats may be available within 24 hours of departure at check-in, or through an Airport Customer Service Agent on the day of departure.

Importantly, it's not for one particular flight, but for every flight between OAK and SEA staring in April and into May that I've searched.

Is this normal, basic site / seat map maintenance or an indicator of something larger afoot in Oakland?