I don't know that having UCONN will help the Big East all that much in Women's Basketball. They are so much better than every team in the BE and will likely beat up on all the teams in the BE. It helps UCONN to get out of their current conference but the Big East is only a mid-major in Women's Basketball that only had 2 teams in the NCAA Tournament last season. Having UCONN join won't jump them up to a major conference.
Just for kicks, I looked up ND's women's basketball history. They joined the BE in 1995-96.
Before 1996, they had only 2 NCAA Tournament appearances ('92 and '94), and were one-and-done both times. Beginning in 1996, they began a run of appearances that continues to this day. And they gradually started making deeper and deeper runs. A first win in '96, a first Final Four in '97, a first Championship in 2001.
So before being in the BE (with UConn, of course), they were a minor player in women's hoops. Once they joined, they rapidly got better to the point where they're one of the best programs in the country, and were able to weather leaving the conference.
And lest you say the success is all about Muffett McGraw...she got there in 1987-88. In her 8 years prior to ND joining, she was slowly making the program better, but there was no indication a national powerhouse was in the making (a couple of NIT appearances and a single loss in the NCAA). Then came the BE invite and they skyrocketed.
So yeah, it is quite plausible that being in the same conference with UConn could help a program make the next step.