Speaking as a someone with similar tenure, I'd be facing the same crisis. I loved my time in DTW, and every time I hear recent stories from people displaced or otherwise moving on from there, it makes me sad. The future is eventually 175, just like 15 years ago the future was eventually the CRJ. I guess I tend to be a cynic by nature. I've held out hope that DTW will remain, but the cynicism is flaring up. Endeavor still seems to think they'll take the East CRJ stuff. They just announced a hiring window of up to 400+ (who knows how many they'll actually hire), so maybe Delta is working on the shuffle some more. Being young, fairly junior, not tied down with a house and other commitments, and ability to have significant ERJ seniority in another base, that's hard to pass up. Absolutely wouldn't commute, though. Are they doing ERJ transition again? If so, probably worthwhile to put your name in the hat and enjoy living in base for now until that day comes.
I've thought long and hard about the same scenario: if AA goes into bankruptcy, dissolves their contracts, divests themselves of Skywest, and PHX goes away or becomes tiny, I'd have to be looking around. I'd commute for a bit but ultimately look at relocating to wherever I hypothetically ended up. No family, no house, not really any strings here other than I've been here 4 years and I like living here. I don't want to leave, but if my position dries up then I'd have to make the same tough decision you're faced with.