There's a couple of concepts at play here called "market" & "leverage".
I'm pretty sure the market for AD, given what interested teams are able to actually offer for him, doesn't necessitate the need to include both Brown & Tatum in a package.
From a leverage standpoint, the closer we get to AD's impending FA, the leverage that NO has to demand both dwindles & dwindles, since the ultimate worse case scenario for them is AD leaving for nothing.