SPOILER ALERT:  This story contains spoilers for the “ Paradise ” Season 2 finale, now streaming on Hulu. Xavier Collins ( Sterling K. Brown ) has a new mission heading into “Paradise” Season 3 — but whether he’ll accept it is left up for debate by the end of the second-season finale of the Dan Fogelman drama, which released Monday on Hulu. In the final episode of “Paradise” Season 2, titled “Exodus,” it’s revealed that the “Alex” that Sinatra (Julianne Nicholson) has been hiding away is a