Kind of two distinct themes: (1) a potential potent scorer should be added to the starting line-up (2) Kelly would be the one to leave the starting lineup to accomplish that.
I strongly disagree with (2). Part of the reason for that is that I don't buy (1).
My bottom line about bball is that it's ultimately all about putting the ball through the hoop the most -- the various ways to accomplish that are secondary considerations. Having five superior scorers playing seems like the most logical way to score points, but it doesn't follow that would be the most logical way to score the most points ... stopping the opponent from scoring points factors in, for example. Ya gotta weigh offense vs. defense. Not news, I know.
I think that in UConn's situation, the team has sufficient ways to score without KML, and am skeptical that any added scoring KML would provide outweighs the contributions Kelly makes, especially since Kelly's contributions, on this team, are more important to team success than is finding additional points. Only one ball = only one person can score each possession (discounting free throw oddities). You get diminishing returns from having more scorers as the number of scorers rises. The additional benefit of having 5 scorers vs. 4 scorers is not as significant as the added benefit of a second scorer or a third scorer. Concurrently, as the value of scoring ability decreases, the value of other contributions rises. When you have a team of Kelly Mezzantes and Kristi Tollivers, your Kalana Greenes and Jess Moores become more crucial to winning.
If you want Kaleena playing -- not a bad idea -- then it would help the team more to have her replace another scorer and not bump someone who provides a rarer commodity, such as rebounds or defense or 'glue.' With the Huskies, there's no shortage of scorers, relatively.