Cordero has been given a longer leash than Benintendi got last year, and has managed to be less productive. Two big reasons might be 1) no minor league to demote him down to for April, and 2) a lack of alternatives on the 40 man roster. The only other outfielders are Marcus Wilson and Jeisson Rosario, and neither is likely to get called up.
They probably won't DFA Cordero after one month. But if they want to try another minor league outfielder like Duran or Gettys or Santana, someone does have to be removed from the 40 man roster to accomodate him. They can use Marwin Gonzalez or Kike Hernandez in the interim, but if someone else is coming up, someone first has to go.
And if it isn't Cordero, then who?