Yes, pilots would be the authoritative source for rumors.
I think DL should worry about finishing their current merger before figuring out who else to buy- aside from the fact that a bunch of AS's network becomes instantly unprofitable the moment someone like AA or DL buys them, thanks to their higher labor costs/etc., plus you'd lose revenue from AA codeshares when AA tells DL which short pier to take a walk off of.
It's a great plan if DL wants to hand over more markeshare to WN, though.