Yes, true, Morales does not need to be rushed (or maybe he already as, from AA). But if the premise is that the closer has to be someone who is somehow suited for the role, he is the only pitcher in the system being explicitly groomed for it.
Emanuel is going to be a starter, I think I read. Per Fangraphs he has options. So does Sherriff. I don't imagine they will have Sherriff jump Alvarado unless he looks really ready.
And yeah, the bullpen is actually good. I think the broadcast yesterday mentioned they were Top 5 in holds and while holds is not the greatest stat, at the end of the day it still says a smallish lead was protected, and last year, that was very much not the case, as the team's epic blown save problem was in every inning, not just the 9th. Familia looks like the weak link but at this time last year Bradley didn't look so great either. It's always hard to tell if you've got a guy who can find his way during the season or if it's just going to be one of the bad seasons.