They probably told Sell that "that's not happening" too. Surprises happen all the time, especially on the women's side. It's Desi's race to lose, but there are still two spots. It's easy to say "Shalane and Kara," but I don't think that they (or Amy, Magda, or anyone else really) are so far ahead that it's outside of the realm of possibility. A 1:31 debut on the NYCM course can't be discounted.
If Molly didn't "look all that good finishing," it's because she's a 23 year old marathon rookie who took off too early (mile 18?) when the crowd got her stoked. She won't be doing that again. Or it could be because she had to build up unusually fast, since she was in the pool with a stress fracture in July.
Molly also has a remarkable ability to recover quickly. She's run well at a bunch races in a short period of time in the past. Obviously the marathon is a different beast, but she respects that, and plans to tailor her recover appropriately. She may not be the obvious choice, but don't discount her altogether. She may very well surprise you.