Sorry if this has been asked over and over, but I am booking an EWR-LAX trip this week. Using a B-fare, it says that only the first flight of the day is available. Using lowest FC fare, it gives me a D-fare on the 3:25 which I never heard of. Isn't B-fare upgraded to any available FC seat for Plat? I thought M-fares were the only restricted seat instant upgrade. Now, if I book a Y-fare, it instantly upgrades me on the 3:25. What's the story?

Another question....just curious...I've requalified for Plat on CO for next year. This trip would put me over 100K for sure. Would you take AA to get status on AA or put it on CO?

Many thanks.