If they score 800 runs, its going to be basically impossible for this team to miss the playoffs no matter what the bullpen does.
Last year the starters had a 3.60 ERA and allowed 410 runs in 960 IP. I see no reason to think this year will be substantially different from the starters. Last year was hardly an amazing year - Scherzer and Roark were good, Gio was bad, Stras and Ross were injured. Replacements were replacement level. Sounds about right.
So if this team scores 800 runs, we would have to allow 700 even to get down to a 92 win projection. That means the bullpen would have to allow 290 runs in about 500 innings, which is 88 more runs than last year.
It's not impossible, there were some teams with bullpen ERAs around 5.00 last season. But it seems like a <5% outcome, and that's just to get down to 92 wins if the team scores 800 runs. If you really want to be a fringe playoff team, the bullpen probably has to give up another 50 runs on top of that, which I'm guessing would be one of the worst bullpens in recent memory.
It's more likely we end up like the Rangers/Blue Jays last year, with a pretty poor bullpen that doesn't prevent us from making the playoffs due to our offense being so good.