I have slept on this, and this deal is still really stupid.
From the perspective of a risk mitigating factor in case you're afraid Jake Oettinger will falter, Holtby has been bad for two year on two different teams. It's funny we've been reminiscing about Kari Lehtonen, because he played behind an awful Stars defense and never had a sub .900 save percentage in those years. Goalies who are washed put up those kinds of numbers over a season, regardless of the defense. He got absolutely spanked by Samsonov in Washington, who had a .913 to Holtby's .897 behind a very average (17th in GA) defense. Demko also beat him soundly with a .915 behind a pretty terrible Vancouver defense. He's much more likely to falter than Oettinger is.
From the perspective of covering for Bishop, this is bad because he's too expensive to bury in the AHL if need be. You'd still have a good amount of his cap hit hindering us in the NHL, and we can't afford a single dollar of it if Bishop does come back. Also, again, he's been really bad.
From the perspective of opportunity cost, this could have just as easily been a partial payment on a good forward, or just cap flexibility to call up rookies or make a trade later.
This guarantees Oettinger is stapled to the AHL (no matter what Nill has to say about him having to 'earn his spot'), because by the time that whole situation is sorted out, I don't think either veteran goalie is able to be traded. Everyone is going to have at least 2 goalies by the time training camp comes around. The smart move would have been to grab a tweener goalie off waivers that no one cared about. Someone who you can bury in the AHL if need be, but good enough to have gotten that far in training camp. Holtby has a good shot at being even worse than a lot of those goalies will be, and at $2M to boot. This season in Vancouver was supposed to be his chance at a bounceback after a really bad season in Washington, he just repeated the same thing.
Strategically, a Khudobin-Holtby tandem would be lucky to be NHL average, an Oettinger-Khudobin tandem has a shot at being above-average, assuming Oettinger improves and Khudobin isn't as bad as last year. If we trade Khudobin and we have Holtby-Oettinger, we are going to be leaning on Oettinger a ton unless Holtby really gets his shit together. This is a goalie-friendly team under a goalie-friendly system, and even then I'd have major doubts about Holtby being anything other than a liability. Hope I'm wrong, but what kind of process is your NHL team using if you grab a guy who has been this bad for two years straight under two completely different teams? Couldn't we have picked someone less risky if we were going down this road?
Edit: And here's a list of all the goalies signed so far this UFA period:
Contract Signings - CapFriendly - NHL Salary Caps