EDD at her best could not replace Crystal as a PG in the current UCONN line up nor could she replace the perimeter defense that Kia Nurse provides.
Also don't think EDD can replace the defensive versatility and offensive setup skills of Gabby. EDD could however replace both KLS and and Napheesa Collier in the current UCONN lineup or Azura as the sixth man.
On the current UCONN team Gustafson could replace Napheesa because she has the shooting percentage to match (leading the country in scoring) and provide more rugged rebounding (5th in the country) and is better/taller post defender. Gustafson could also replace Azura as the UCONN 6th man because Azura's 3 point shooting has proven to be less than neth. Gustafson is also a better finisher than Azura and has a more diverse set of offensive moves at the basket. Azura is a much more dynamic passer and overall better suited for UCONN's offense but in reality next year they could be dynamic together if Gustafson were at UCONN.
Interesting side note: Had EDD decided to stay at UCONN she would have been joining a starting line up with Maya, Tina, Renee, & Kalana Greene. Would this have been the best starting 5 UCONN ever had?