He really can't lose this year. This unit last season was bottom third (20th in scoring) and they lost good players. I don't think they lost great players, but certainly good starters in Ramsey and Floyd with rookies coming in to replace them. So it's not like you can sit Raheem down after the season and browbeat him about having a poor defense, if that ends up being the result. As long as they're not completely inept his job won't be at risk.
Prior to them accepting a reloading of the roster I would have agreed that this is a big season for him. But the way it went down his defense is young and will need another draft plus a key FA or two in order to have top third expectations.
Now if the draft picks include some home runs it is possible this thing turns around quickly. Because I don't think Raheem is a poor DC. I think he's mediocre in terms of calling it, see him as a guy who will probably be a better HC than he ever was as a coordinator. If he gets 15th or higher production in scoring allowed from this unit, however, he's gonna get a HC gig. Because that would be a very strong productive season given what he's cooking with.