In terms of getting a better seed it can help to have a great record in a crap conference or even just a better record in the 3rd or 4th best vs toughest.
The Big 12 has statistically quite clearly been the best conference for about 13 years straight yet only got widely acknowledged as such in the past 2-3 years. The tournament evens it out a little if you look at wide range of performance over several years, but there's still space to get a boost or get screwed in terms of # of selections and seeding matchups.
Zags could still be elite but the days of regularly coasting to top 4 seeds will be gone. I'm also not sure what the effects of being THAT isolated compared to other programs would be. It's not football where they'd have 5 long road trips. It's a long cross country road trip pretty much every week of the season. Makes my head spin thinking about how Big Ten non-revenue sports are going to do it (or even worse Stanford/Cal playing mostly east coast games).
I've heard some experts say they think there's something legit about Zags busting in the pros because the WCC doesn't expose weaknesses like the Big 12/Big East/Big Ten would.
I think going to the Big 12 is a mistake for Gonzaga because they've got it pretty good where they're at.
My point was responding to the suggestion that Gonzaga would struggle in the Big 12. They would not. They wouldn't win every year or win 90% of their games but they'd do well.