From an all-sports perspective -
The B1G sponsors 28 conference sports. Of those 28, UConn sponsors 23. UConn also has a women's ice hockey team, which the B1G currently does not sponsor.
The sports UConn does not sponsor include:
Men's Sports - Gymnastics, Lacrosse, Wrestling
Women's Sports - Golf, Gymnastics
All 14 current B1G schools have wrestling teams and women's golf teams, so UConn would be an outlier there. For the other three sports, 7 sponsor men's gymnastics, 6 sponsor men's lacrosse, and 10 sponsor women's gymnastics.
For women's ice hockey, 4 B1G teams currently sponsor that sport, so the addition of UConn would leave the conference one team short of being able to sponsor that as a conference sport as well.
Sponsoring 23 B1G sports would tie UConn for 8th with Indiana out of the current 14 schools in the conference.
Here is a breakdown of how many of the 28 sports each B1G team sponsors.....
1. Ohio State - 28
1. Michigan - 28
3. Penn State - 27 (women's rowing)
4. Michigan State - 25 (men's gymnastics, men's lacrosse, women's lacrosse)
5. Iowa - 24 (men's ice hockey, men's lacrosse, men's soccer, women's lacrosse)
5. Minnesota - 24 (men's lacrosse, men's soccer, women's field hockey, women's lacrosse)
5. Rutgers - 24 (men's gymnastics, men's ice hockey, men's swimming & diving, men's tennis)
8. Indiana - 23 (men's gymnastics, men's ice hockey, men's lacrosse, women's gymnastics, women's lacrosse)
9. Wisconsin - 22 (men's baseball, men's gymnastics, men's lacrosse, women's field hockey, women's gymnastics, women's lacrosse)
10. Illinois - 21 (men's ice hockey, men's lacrosse, men's soccer, men's swimming & diving, women's field hockey, women's lacrosse, women's rowing)
10. Nebraska - 21 (men's ice hockey, men's lacrosse, men's soccer, men's swimming & diving, women's field hockey, women's lacrosse, women's rowing)
12. Purdue - 20 (men's gymnastics, men's ice hockey, men's lacrosse, men's soccer, women's field hockey, women's gymnastics, women's lacrosse, women's rowing)
12. Maryland - 20 (men's cross country, men's gymnastics, men's ice hockey, men's swimming & diving, men's tennis, men's indoor track & field, women's rowing, women's swimming & diving)
14. Northwestern - 18 (men's cross country, men's gymnastics, men's ice hockey, men's lacrosse, men's indoor track & field, men's outdoor track & field, women's gymnastics, women's rowing, women's indoor track & field, women's outdoor track & field)