Big 10 level ice hockey will take a level of facilities commitment far beyond just blowing out a few walls to expand Freitas. Penn State will be opening a gorgeous new arena that sounds similar in specs to Agganis. MN, UW and tOSU play in very large, relatively new buildings (with the former two filling them on a regular basis) and the Michigan schools draw extremely well in their traditional 6,000+ seat barns. MN, UW, UM and MSU all have multiple national championships to their credit.
Unless it was almost completely flattened and replaced with an essentially new building, an enlarged Freitas would probably be in the bottom 1/3 of HE - trailing modern facilities at ND, BU, BCU, UNH, UML and UMass (albeit the latter is oversized for its market) as well as classic facilities at UVM and NU. Even Merrimack's barn, the traditional bottom of the HE barrel has undergone renovations but I haven't seen it since the recent work.
If UConn does decide to go forward hopefully it will be in a first class manner to be competitive rather than an attempt to get by with the minimum upgrade possible to gain admission. Of course the same could be said for staffing requirements, scholarships, operating budget, etc.