I think the deal is
-Coop needs to be extended this year.
-Dak needs to be extended this year.
-Jaylon, it would probably be better to extend him now rather than wait for him to hit RFA and basically let another team dictate our contract offer.
-Byron, needs to be extended this year if we're keeping him, although I haven't heard a single word about us doing that.
Zeke, OTOH, still has two years left on his contract.
But more importantly than that, the RB market is not going to change after this season. Look at your top 5 non-Zeke RBs in the game - I'd call them Saquon, Gurley, McCaffrey, Bell, and Kamara. David Johnson might have an argument to be on the list. Anyway, all of those guys save Kamara already have their big contract, or are like 3 years away from their big contract. The Saints have the option to extend Kamara after 2019, but they may wait all four years of his contract until they pay him.
So long story short, the top dollar for an RB isn't going to change between 2019 and 2020. No player is going to reset the market, so we're not really going to save any money if we pay him early. Couple that with 2 remaining years of team control, and holding off on an extension is a smart move.
I think the understanding is that the team will deal in good faith with Elliott and offer him a Gurley style deal, but they won't get around to hammering out specifics until they see how the final numbers for their other extensions look. Leaving Zeke on the back burner is good is business, but it's important to keep him placated with some real contract talks to keep him from holding out in the meantime. Imagine how different our outlook for the season would be with our brand new Mike Weber/Tony Pollard backfield.