Difficult to justify the cost of building a hockey only facility, especially if you need a new basketball and hockey facility. A school like BU could do it because hockey is their premier sport. A lot of the teams you mentioned are hockey focused or are playing in a an older arena like Michigan.
If "that's how successful teams manage it", and "half-empty arenas suck for home advantage" aren't a good enough reason, I have more.
1) Scheduling priority: If UConn hockey shares the same arena footprint as basketball (i.e. a basketball floor on top of the ice plant), they will be at best a third priority (and will drop to fourth if that arena is the XL). Games will be shoehorned onto weekend afternoon and weeknight slots, and attendance WILL not be as high as it could be as a result (weeknight games will be non-starters for the youth hockey portion of the fan base). This would be easier to manage should we be invited to Hockey East (only Maine and Notre Dame will need to be done as two-fers rather than home and homes). I have no doubt that it can be managed well enough, but if a basketball game needs the arena on a specific date, they're going to get priority over hockey, no questions asked.
2) Local youth hockey: UConn's current arena is put to use by local youth (Northeast Ice Dogs) and high school hockey (EO Smith's co-op with Tolland and Windham), partially subsidizing the operations cost. I see no reason that can't continue into a new facility, and those programs will need somewhere to go in any event.
3) Practice time: To some degree, this will be partially alleviated by a separate basketball practice facility as is being currently built. However, women's hockey, men's hockey, youth hockey, men's basketball, women's basketball, and volleyball will all need practice time; you could maintain Frietas as a practice/community rink...but why have the extra cost of maintaining two rinks?
4) Student fans: Having the games off campus to start, without a transition plan to on-campus, will prevent the school from ever building a solid student fan base that is the core of successful hockey programs around the country.
I get the main point: it requires a large capital outlay to start, and that will have to be considered as part of this study. That's why the school is not doing it, but exploring it.
Then you have Minnesota that has a facility for basketball, men's hockey and woman's hockey. Men's facility sits 10K the woman's 3.4K. Woman's facility was built after the men's facility.
But none of them play on the same footprint, now that Ridder has been built. Williams (the hoops venue) used to host all three; now they just have hoops.